Well‐established studies in behavioral finance confirm that investors are highly influenced by subjective reference points when making economic decisions. Although the literature examines reference point formation for individual stocks based on observed price sequences, the stocks are often treated without considering market context. We extend this literature by incorporating market price information as background to the behavior experiment, and we consider both prospect theory and anticipation/disappointment‐based utility functions in a combined framework to investigate the impact of market context on reference point formation. Our article provides new evidence and insights for investment practitioners and behavioral researchers.
Keywords: Behavioral Finance; Market Contextual; Reference‐point Formation
A common assumption in behavioral finance is that individuals measure gains and losses relative to a subjective reference point. This assumption underlies Kahneman and Tversky's (1979) prospect theory, which posits that perceived value derives not from absolute wealth but from changes in wealth, in contrast to standard expected utility (EU) theory (Savage, 1972; Von Neumann & Morgenstern, 1947), which assumes that utility is based solely on final wealth.
Because reference points play such a critical role in behavioral finance, researchers are naturally interested in understanding the processes by which reference points form and evolve. For instance, Kőszegi and Rabin (2006) propose a model in which reference points form and adapt by a process of anticipation. Baucells and Hwang (2016) suggest that reference points are determined by a psychological process and link it to a variety of behavioral biases, including sunk‐cost effects, payment depreciation, reluctance to trade, preference for prepayment, and flat‐rate bias.
In reality, reference points may shift over time in response to price changes and other factors, reflecting the phenomenon that decision makers habituate to new wealth levels just as individuals adapt their sensory perceptions to physical changes in brightness or temperature. In investment contexts, a shift in the reference point toward a newly realized price is called adaptation. Adaptation is naturally a dynamic process and therefore reference points should be viewed as a function of both current and past prices such as a weighted average of values in an observed price sequence (Feng & Seasholes, 2005; Grinblatt & Keloharju, 2001; Odean, 1998; Shefrin & Statman, 1985). In an experimental setting, Baucells et al. (2011; hereafter BWW) analyze reference point dynamics in which subjects formulate reference points for hypothetical stocks based on contrived price patterns. BWW show that although the reference point initially anchors to the purchase price, it subsequently adapts as the price path evolves to include intermediate prices and the current price, and may also have a built‐in profit expectation. Recent work by Riley et al. (2020) shows that the traditional capital gains overhang model can be significantly improved by incorporating reference point adjustments based on the BWW framework.
Despite the success of the BWW framework in explaining reference point formation for individual stocks, its simplified setting only considers each stock price movement as isolated from market contextual information and hence overlooks the market backdrop as one key feature of investments in reality. Toward that end, we incorporate market information as background to the BWW experiment to develop a new platform for analyzing the impact of market context on reference price formation.
There are several reasons why market context might affect reference point formation for individual stocks. Because covariation between stocks and the market is well known, investor expectations about the stock price may depend on the observed market state in combination with comovement measures such as beta or correlation. The current market trend combined with observed comovement may induce feelings of optimism or pessimism about the stock. Investor beliefs about mean reversion (Odean, 1998) or momentum (Grosshans & Zeisberger, 2018) may transfer to individual stocks, biasing expectations. Comparisons between own stock performance and the overall market may influence investor satisfaction (Merkle et al., 2015), affecting expectations and the propensity to sell or hold the stock (Grosshans & Zeisberger, 2018). Moreover, the limited attention theory (Kahneman, 1973) suggests that when market information is available, investors may pay less attention to some stock‐related variables, focusing instead on market factors such as current market trend. Investor attentiveness or nonattentiveness to the stock may be selective based on the observed market state due to the psychological utility of positive or negative information, as suggested by the asymmetric ostrich effect (Karlsson et al., 2009). In addition, investors may worry more about losses for stocks that are highly correlated with the market, as suggested by the downside risk hypothesis (Ang et al., 2006). Last but not least, because of heuristic biases such as anchoring (Tversky & Kahneman, 1974), in which reference points gravitate toward irrelevant or noninformative values, investors may adapt their reference points to the market backdrop as an unconscious anchor even when they have no investment experience and consider the market as irrelevant information.
Recent studies document that context‐specific effects vary by market condition. Lee et al. (2013) report that investors with extreme capital losses are more active in redeeming mutual fund shares in a bear market than in a bull market, whereas investors with moderate capital gains are less active in redeeming fund shares in a bull market. In neutral markets, they find that investors redeem both winner and loser funds except when they have extreme capital losses. Karlsson et al. (2009) conclude that adaptation is faster in rising markets than in falling markets because investors pay more attention in rising markets. However, Arkes et al. (2008) find that adaption to gains is greater than adaptation to losses whether the market is up or down, suggesting that attention is not the only factor. Kliger and Kudryavtsev (2008) find that reference point adaptation is more reactive when stocks are more sensitive to market fluctuations, that is, for high‐beta stocks. All of these findings suggest that reference point effects are context dependent. This limits the generalizability of BWW's findings and complicates the task of sorting the interplay between stock price factors and context‐driven effects, highlighting the need for more work in this area.
In addition to incorporating market context in the experimental methodology, we contribute to the literature by broadening the analysis to consider both prospect theory and emotion‐based explanations of reference point behavior in a unified framework, whereas BWW focus only on prospect theory. Although prospect theory has largely been supported empirically, research has shown that some of its key results are unstable across different contexts or framing domains (Fischhoff, 1983; Hershey & Schoemaker, 1980; Schneider & Lopes, 1986), thus motivating the need for an expanded framework.
One of the well‐known results associated with prospect theory is the disposition effect, which is based on Kahneman and Tversky's (1979) reflection effect or the tendency for decision makers to reverse preferences in loss versus gain domains relative to some neutral reference point, in a manner that exhibits risk seeking in the negative domain and risk aversion in the positive domain. The reflection effect and the related concept of mental accounting (Thaler, 1985) form a theoretical basis in prospect theory for what Shefrin and Statman (1985) call the "disposition effect," which states that investors tend to dispose of gains quickly but resist selling at a loss.
Empirical support for the disposition effect has been documented in studies using aggregate market data (Kliger & Kudryavtsev, 2008; Lakonishok & Smidt, 1986), individual investor trading accounts (Barber & Odean, 1999; Karlsson et al., 2009; Odean, 1998), and experimental settings (Arkes et al., 2008; Weber & Camerer, 1998). However, empirical validation is not uniform, and recent studies show that cognitive biases related to the visual processing of graphical information can affect investor behavior and reference point formation in ways not necessarily consistent with disposition effect behavior. In addition, investor perceptions of risk are frequently shaped by intuitive or heuristic processing of graphical features of price series, rather than orthodox optimization rules based on statistical moments. This is relevant in real‐world settings where investment performance is frequently displayed graphically to investors, and in experimental settings such as in our article where stock and market price sequences are presented in graphical format to subjects.
Duclos (2015) documents an end‐anchoring bias or the unconscious tendency to attach disproportionately high importance to the last trading day in a visual price sequence when forming expectations such that when controlling for other factors, an upward (downward) sloping last trade direction results in a higher (lower) willingness to purchase the stock. This is consistent with momentum investing or a belief in short‐term trend continuation.
Grosshans and Zeisberger (2018) document order preferences for gains and losses in visual price patterns and demonstrate that investor satisfaction is highest for down‐up patterns and lowest for up‐down patterns, when controlling for other factors. They conclude that higher levels of satisfaction associated with down‐up patterns correlate with more optimistic forecasts and lead to greater holding propensity for the stock. Their results are consistent with end‐anchoring and momentum beliefs. They find that reference point adaptation for stocks is more complete in the gain domain than in the loss domain, and they suggest that in up‐market environments, overall momentum beliefs may transfer to winner stocks and amplify the increase in reference point adaptation. In an experimental setting, they find that the disposition effect sometimes occurs without mean reversion beliefs, and they document that an inverted or reverse disposition effect can occur for relatively straight price patterns.
Duxbury and Summers (2018) analyze risk perceptions of observed price sequences in an experimental setting and document that investor perceptions of risk and volatility are driven by salient features of price path characteristics rather than by standard deviation of return. Although standard deviation of return may have a role to play in perceptions of price sequences, the authors show that other price‐based factors play a far greater role. Based on such price sequences, they find that price‐based factors, such as the number of peaks or the number of accelerated changes in direction within the price sequence, better predict risk and volatility perception. Furthermore, they report evidence to support the view that the extent to which prices appear irregular is a separate aspect of volatility, distinct from the extent to which prices deviate from central tendency. Borsboom and Zeisberger (2020) show that investors focus on heuristics in looking at visual stock price patterns and that investor risk perceptions are driven by salient features of price path characteristics such as high and low prices and short‐term crashes rather than standard deviation, consistent with Duxbury and Summers (2018). They also document investor belief in short‐term trend continuation consistent with end‐anchoring.
Sobolev and Harvey (2016) use a fractal structure to simulate price patterns and show that investor risk perceptions depend on the Hurst exponent, which measures the degree of roughness or smoothness in a price series. They find that when viewing only graphical information, subjects who measure highest for risk sensitivity based on their emotional instability perceive price charts with greater "roughness" to be riskier. Overall, they find that risk perceptions are more strongly influenced by the Hurst exponent than by traditional volatility measures from modern finance theory such as standard deviation.
All of these results suggest that market context effects may be further clarified by our study, in which subjects view simultaneous stock and market price patterns presented in graphical format, and highlight the need for an expanded framework that accommodates visual pattern effects and emotional factors. Although loss aversion under prospect theory is frequently cited as a primary rationale for the disposition effect, Summers and Duxbury (2012) document that emotions are a necessary cause of the disposition effect. Their findings show that prospect theory alone does not provide a sufficient cause for the effect and that specific emotions related to the task (i.e., elation for winners and regret for losers) are necessary for the effect to manifest. Shefrin and Statman's (1985) explanation for the disposition effect includes components of regret aversion and self‐control as supporting elements. Muermann and Volkman Wise (2006) develop a model in a dynamic portfolio setting to show that the disposition effect can be explained without loss aversion by positing preferences based on anticipated emotions of regret and pride. Other rationales for the disposition effect that appear in the literature include mean reversion beliefs (Odean, 1998) or preferences based on heuristics such as realization utility (Barberis & Xiong, 2012) where investors experience selling a given asset above (below) its purchase price as a positive (negative) investment "episode."
The disposition effect can be rationalized based on a combination of prospect theory and mental accounting with emotional factors playing a supporting role (Shefrin & Statman, 1985), or alternatively based solely on emotional mechanisms such as the balancing of conflicting feelings of regret and pride (Muermann & Volkman Wise, 2006). There is a broad literature on the role of emotion in shaping preferences, with seminal works that include anticipatory feelings of regret (Bell, 1982; Loomes & Sugden, 1982) or disappointment (Bell, 1985; Gul, 1991). Related to this literature, we incorporate in our analysis the Gollier and Muermann (2010; hereafter GM) model of ex ante savoring and ex post disappointment that combines Bell's (1985) disappointment theory with Akerlof and Dickens's (1982) concept of anticipatory feelings.
In analyzing market context we examine reference point adaptation through the lens of both prospect theory and the GM emotion‐based model. This overarching framework adds clarity to BWW's original findings and provides a decomposition of their results based on stock‐ and market‐related factors. We document evidence of market context effects both graphically and in regression analyses.
Our overarching framework combines the BWW and GM models, which both are behavior‐based alternatives to standard EU theory but differ in how they accommodate market context effects. A primary way that behavior‐based models differ from EU is through the assumption of probability‐dependent preferences (PDPs), where perceived utility depends not only on the shape of the utility function but also on subjective decision weights that may differ from objective probabilities. It is through the subjective decision weights that market context can matter.
Fehr‐Duda and Epper (2012) identify two main classes of PDP models: rank‐dependent models (Quiggin, 1982; Tversky & Kahneman, 1992), which include cumulative prospect theory as a variant, and disappointment aversion models (Gul, 1991). The BWW and GM models represent these two broad frameworks, respectively. These frameworks are differentiated by the manner in which subjective decision weights are formed. In rank‐dependent models, the decision weights are based on a ranking of possible outcomes, and gains and losses are measured relative to an exogenous reference point. In disappointment aversion models, decision weights and the reference point are determined endogenously and concurrently to optimally balance a trade‐off between feelings of anticipation and disappointment. We investigate market context‐related effects under each of these two broad frameworks.
Our experimental framework is similar to BWW who presented subjects with scenarios portraying a hypothetical sequence of stock prices
BWW consider two possible mechanisms of reference point formation to describe how subjects arrive at their reported values of
BWW define five price factors based on the chart sequence: purchase price (
Rank‐dependent models like BWW can help to explain non‐EU behaviors such as the disposition effect but are limited in their ability to explain market context effects involving emotional or expectational elements, as the decision weights under prospect theory are normally based on a limited range of psychological factors. Alternatively, the GM model postulates an explicit behavioral process for the formation of decision weights based on feelings of anticipated disappointment and ex ante savoring. These feelings correspond to the human traits of pessimism and optimism, which are perhaps the most common characterizations of market sentiment, making the GM model a natural choice for analyzing the impact of market context on reference point formation.
The GM model assumes a set of lottery payoffs
The first term in Equation (
Next, we identify specific behavioral mechanisms that account for market background effects underlying each of the two modeling frameworks, starting with BWW. Market context in BWW is best understood in terms of the dual‐process theory of human behavior (Alós‐Ferrer & Strack, 2014) that differentiates affective and cognitive components of decision processes. In cumulative prospect theory, these components are identified as two parallel stages: an unconscious editing stage where objective payoffs are transformed via a weighting function, and a cognitive evaluation stage where the transformed payoffs are ranked via the prospect theory value function. The editing stage involves unconscious emotions and decision heuristics to simplify the choice set before the more reasoned/reflective processing stage. Context shifts in prospect theory are dealt with at the editing stage, as noted by Vlaev (2018) who refers to the editing stage as an example of local rationality.
The dual‐processing view clarifies the distinct role of beliefs versus preferences in prospect theory, and the corresponding role of context. Beliefs are exogenous but can be "bent" or shaped in the editing stage via the subjective weighting function to reflect behavioral biases or contextual information, whereas preferences are defined by the value function and are normally considered to be relatively stable across contexts (Ungemach et al., 2011). Although decision weights are akin to subjective probabilities, Kahneman and Tversky (1979) emphasize that they are not beliefs and may be in direct contradiction to stated objective probabilities. For our experiment, objective probabilities governing future stock payoffs are specifically stated in the instructions to subjects, as was done in BWW and similar studies to minimize expectational bias.
Through the weighting function, subjects can manipulate objective probabilities behaviorally, for example, by over‐ or underweighting different payoffs based on their degree of objective uncertainty as in Kahneman and Tversky (1979). One such incremental effect associated with market context might be a visual impression of covariation between stock and market prices that may cause subjects to change their subjective weightings in the editing stage, but this happens unconsciously and does not necessarily correspond to a change in objective beliefs. We purposely relegated market context information to the background by portraying it only in graphical form, and we made minimal reference to it in the instructions to subjects to avoid making it focal to the decision task.
The presence of market information in the background can influence the editing process in various ways, one of which is through affect. For instance, the simple act of viewing a rising or falling market can evoke feelings or emotions such as optimism or pessimism. Or as mentioned earlier, the market viewed in conjunction with a stock price pattern may unconsciously suggest something about future stock price movement because of perceived covariation. This does not mean that subjects necessarily compute or even conceptualize a formal covariation parameter such as beta or correlation, as the editing stage operates unconsciously on the basis of emotion and heuristic simplification to set the stage for cognitive processing. The notion that subjects perceive volatility or comovement information directly from the visual pattern in the editing stage without formal computation of statistical parameters is consistent with Duxbury and Summers (2018), Borsboom and Zeisberger (2020), and Sobolev and Harvey (2016), as well as Grosshans and Zeisberger (2018) who state that the specific mechanism in prospect theory for the cognitive biases they address is the weighting function. In addition, reference point formation in general may reflect aspirational thinking as mentioned by BWW, or other factors such as anchoring or attention. These different interpretations are not mutually exclusive and may be reinforcing or offsetting.
In the GM framework, context effects are modeled through their impact on investor emotions of anticipated disappointment and ex ante savoring. The relevant information in forming such emotions in our experiment is the market price graph. A natural question is whether contextual market information may introduce a form of expectational bias in beliefs, which it may, but in the GM model it does so by design with regard to subjective probabilities
In terms of the specific mechanism for market context in their model, GM point out that the parameter
One way to conceptualize our combined modeling framework is to start with BWW and then add market context to see if/how it changes the outcome. BWW document primacy and recency effects where subjects anchor to the initial and terminal prices, which the authors explain by the prospect theory weighting function. Our experiment adds market context, which creates the possibility for emotion‐based and expectational effects that are not easily explained by prospect theory but that are easily accommodated in a GM framework that allows endogenous belief formation. In GM, decision makers can reoptimize their utility in response to incremental information by forming a new combination of reference price
Consider a thought experiment where a GM decision agent forms a reference price based on past stock price information, as in BWW. Now, add market context information that changes the decision agent's outlook, making her more optimistic or pessimistic. The agent can recalibrate her subjective probabilities to form a new reference price and achieve a new level of utility, which may be either higher or lower than before, but one that is optimal (and rational) given the new information. The resulting change in the reference price represents the marginal effect of the new information. We designed our experiment with the aim of capturing this incremental effect. The market pattern in our experiment is presented concurrently with the stock pattern; therefore, the new information does not arrive intertemporally but is incremental in a comparative static sense. Also, the market information is not focal to the decision task but is "additional" in the sense that it adds a contextual element to the modeling framework, not in the sense that enlarges the focal information set for the decision task (as would, say, adding an additional price point to the stock chart). Market context operates largely through unconscious mechanisms and can change outcomes without changing objective beliefs about returns, for example, through its impact on emotional state or heuristic biases. Our overarching hypothesis is that market context matters, which we can demonstrate by conditioning BWW's results on different market states.
The change in perceived utility related to the addition of market context requires no conscious action on the part of the agent. However, it does require the agent to deliberately balance "wishful thinking" with realistic expectations in a way that, as GM point out, involves managing some cognitive dissonance. But this is something humans do all the time to feel better about situations they may not control. New information may provide a signal that triggers a rebalancing of the trade‐off between apprehension and elation. A person may contemplate this trade‐off even if he does not act on it. Such contemplation, whether unconscious or volitional, is equivalent to changing the amount the person is willing to pay if he imagined placing a hypothetical bet; that is, it is equivalent to changing his reference point.
Following our previous discussion of possible reasons and mechanisms, we create several hypotheses on how the market context may affect the reference point formation of individual stocks, which we investigate through our experiment as detailed in the following sections.
H1: Covariation effects: Perceived covariation may lead investors to base reference point decisions on the observed market state in combination with covariation measures such as beta or correlation.
Previous findings mentioned earlier (e.g., Kliger & Kudryavtsev, 2008; Lee et al., 2013) suggest that reference point formation may depend on covariation between stock and market patterns. Other studies (e.g., Duxbury & Summers, 2018) suggest that such covariation effects may be gleaned from visual patterns even if investors do not formally compute statistical parameters. Such effects may operate unconsciously through the prospect theory weighting function (Grosshans & Zeisberger, 2018) or, in the GM framework, through their impact on optimism/pessimism.
H2: Divided attention theory: When market information is available, investors may reduce their attention on some intermediate stock price factors (AIP, HP, and/or LP), focusing instead on the main stock price factors of PP and CP, as suggested by the Kahneman (1973) model of divided attention.
The Kahneman (1973) model of divided attention suggests that attention is a limited resource and that individuals performing a task may selectively concentrate their attention on a salient subset of input variables while ignoring less salient variables. In forming reference prices based on stock price patterns, BWW document primacy and recency effects where subjects place greater decision weight on initial and terminal prices, suggesting that
H3: Asymmetric ostrich effect: Investors may exhibit greater adaptation of their reference point in a rising versus falling market environment because of attentional differences (Karlsson et al., 2009).
Karlsson et al. (2009) suggest that asymmetric attention in different market states derives from investor preferences. They posit a utility function that exhibits positive utility of information in up‐market states and disutility of information in down‐market states. This is in contrast to the divided attention theory, which is based on limited attentional resources.
H4: Asymmetric adaptation in gain versus loss domains: Investors may exhibit greater adaptation of their reference point in the region of stock gains versus losses as a result of hedonic maximization as suggested by (Arkes et al., 2008).
In an experimental setting, Arkes et al. (2008) find that reference point adaptation is greater in states where the stock is in a capital gain (
H5: Investors may exhibit a higher reference price when they are optimistic versus pessimistic about their own stock or the overall market because of feelings of ex ante savoring and ex post disappointment (GM).
The GM model implies that the reference price is higher when the investor is more optimistic and lower when the investor is more pessimistic. We hypothesize that investor optimism or pessimism may depend on the economic state, such that higher stock or market price leads to greater optimism and a higher reference price, and lower stock or market price leads to greater pessimism and a lower reference price.
H6: Investors may exhibit a higher reference price for visual price patterns that follow down‐up versus up‐down patterns (Grosshans & Zeisberger, 2018).
Grosshans and Zeisberger (2018) find that investors feel a greater sense of investor satisfaction for down‐up patterns, leading them to be more optimistic, and less investor satisfaction for up‐down patterns, leading them to be more pessimistic. The GM model implies a higher reference point for more optimism and a lower reference point for more pessimism.
H7: Investors may anchor to the market and bias their reference price to the market direction (Tversky & Kahneman, 1974).
The unconscious cognitive bias of anchoring to the market may lead to higher reference prices in up‐market states and lower reference prices in down‐market states. Market direction in this case may be defined by either short‐term price movement, such as last trade, or long‐term price direction, such as linear trend.
H8: Investors may exhibit end‐anchoring and bias their reference price toward the most recent directional move in a price sequence (Duclos, 2015).
End‐anchoring applies specifically to the direction of the last market price move and is consistent with investor beliefs about short‐term trend continuation in the market transferring to the stock. It implies that the reference price may move in the direction of the last market price move.
In the experiment, we examine the impact of market information on the formation and updating of the reference point adopted by participants. Experiments were conducted in a classroom setting at a major state university in the United States on groups of subjects consisting of a roughly equal proportion of male and female undergraduate finance students who had completed at least one junior‐level principles of finance course. A majority of the subjects are US citizens and about 6% are international students. Three separate group sessions were held with similar room conditions for each session and subjects completed the experiment individually on personal computers. Professors proctored the sessions and subjects were awarded a small amount of extra credit toward their final grade to facilitate engagement and to ensure the quality of the experiments. Of 77 subjects who completed the experiment, 14 were eliminated because of outliers or other reasons described next, resulting in a final sample of 63 subjects. Subjects were given a regular class period (75 min) to finish the experiment and were not allowed to communicate with each other to prevent any exchange of opinions that may influence their reference point formation processes. We believe that the chosen time limit was sufficient but required some budgeting of cognitive resources to provide an appropriate balance between reflexive and contemplative subject responses.
Outliers were eliminated by a combination of formal outlier detection criteria and visual inspection, yielding overlapping results with the exception of one subject. The formal outlier analysis eliminated 9 subjects who reported at least one reference price with p‐value less than 0.0001 in absolute value based on a two‐tailed test applied separately to each visual pattern. The visual inspection method eliminated 1 additional subject who stated a reference price as 100 times the current price, which we suspect is due to a missing decimal point. In addition, 4 subjects were eliminated for uniformly choosing a reference price equal to the current stock price for every price chart; we do not believe these subjects devoted sufficient time or reflection to actually engage the underlying behavioral mechanisms hypothesized by the theories under investigation.
Following BWW, we presented each subject with a series of simulated stock price patterns on a computer screen. Order effects were controlled for by randomizing the order of presentation of charts across subjects (see Grosshans & Zeisberger, 2018; Loewenstein & Prelec, 1993; Read & Powell, 2002). For each pattern, we asked the subject to imagine that they purchased the stock several days ago and then immediately went on vacation to a locale where they could not trade the stock or monitor its price. Upon returning from vacation, the subject viewed a sequence of stock prices that occurred during their absence. Similar to Arkes et al. (2008) and BWW, we elicited a reference point by asking the subject to enter a price that would produce "emotional neutrality" if they were to sell the stock at their stated price.
For comparability with BWW, we used essentially the same language as theirs in our instructions to the subject. Unlike BWW, however, in addition to the stock pattern, we displayed a simultaneous price pattern for the overall stock market, to which students could either pay attention or ignore. To avoid introducing semantic or framing effects, we made no mention of the market information verbally and made only minimal reference to it in the written instructions, simply modifying the BWW language to state that the subject "will be shown the stock price and market index development chart." We added the market price sequence to the chart as subtle background information, giving no indication of its relevance. The exact set of instructions given to subjects appears in Figure 1.
For each stock price path, we are interested in the extent of reference point adaptation, that is, the degree to which a subject's reference point tends toward the most recently observed stock price. Adaptation is measured as a proportion of the cumulative observed stock price change as follows:
where i denotes the ith subject, and PP and CP denote the stock's purchase price and current price, respectively. An illustration of adaptation levels for two illustrative simple stock patterns appears in Figure 2, where Panel (a) represents a capital loss situation (CP < PP) and Panel (b) represents a capital gain situation (CP > PP). Complete adaptation is defined as A
BWW devised a methodology to measure the impact of each price factor (
1 TableThe 160 stock and market price sequences used in the experiment
Sequence Price pattern Baucells stock no. Avg. Stock 1a 1 250 200 150 200 239.1 Market 1a 1 400 350 300 350 Stock 1b 1 250 200 150 200 238.4 Market 1b 1 400 450 500 450 Stock 1c 1 250 200 150 200 242.3 Market 1c 1 400 350 300 450 Stock 1d 1 250 200 150 200 230.5 Market 1d 1 400 450 500 350 Stock 2a 2 150 200 250 200 194.4 Market 2a 2 400 450 500 450 Stock 2b 2 150 200 250 200 198.8 Market 2b 2 400 350 300 350 Stock 2c 2 150 200 250 200 186.6 Market 2c 2 400 450 500 350 Stock 2d 2 150 200 250 200 209.3 Market 2d 2 400 350 300 450 Stock 7a 7 250 200 150 200 160 200 240 200 230.0 Market 7a 7 400 350 300 350 310 350 390 350 Stock 7b 7 250 200 150 200 160 200 240 200 234.2 Market 7b 7 400 450 500 450 490 450 410 450 Stock 7c 7 250 200 150 200 160 200 240 200 241.7 Market 7c 7 400 350 300 350 310 350 390 450 Stock 7d 7 250 200 150 200 160 200 240 200 233.1 Market 7d 7 400 450 500 450 490 450 410 350 Stock 8a 8 150 200 250 200 240 200 160 200 204.3 Market 8a 8 400 450 500 450 490 450 410 450 Stock 8b 8 150 200 250 200 240 200 160 200 202.1 Market 8b 8 400 350 300 350 310 350 390 350 Stock 8c 8 150 200 250 200 240 200 160 200 189.9 Market 8c 8 400 450 500 450 490 450 410 350 Stock 8d 8 150 200 250 200 240 200 160 200 196.6 Market 8d 8 400 350 300 350 310 350 390 450 Stock 11a 11 200 150 200 250 249.5 Market 11a 11 400 350 400 450 Stock 11b 11 200 150 200 250 235.9 Market 11b 11 400 450 400 350 Stock 11c 11 200 150 200 250 237.5 Market 11c 11 400 350 400 350 Stock 11d 11 200 150 200 250 241.6 Market 11d 11 400 450 400 450 Stock 12a 12 200 250 200 150 189.3 Market 12a 12 400 450 400 350 Stock 12b 12 200 250 200 150 188.3 Market 12b 12 400 350 400 450 Stock 12c 12 200 250 200 150 200.7 Market 12c 12 400 450 400 450 Stock 12d 12 200 250 200 150 190.3 Market 12d 12 400 350 400 350 Stock 15a 15 200 150 170 200 250 230 224.1 Market 15a 15 400 350 370 400 450 430 Stock 15b 15 200 150 170 200 250 230 225.9 Market 15b 15 400 450 430 400 350 370 Stock 15c 15 200 150 170 200 250 230 223.1 Market 15c 15 400 350 370 400 450 370 Stock 15d 15 200 150 170 200 250 230 229.7 Market 15d 15 400 450 430 400 350 430 Stock 16a 16 200 250 230 200 150 170 203.6 Market 16a 16 400 450 430 400 350 370 Stock 16b 16 200 250 230 200 150 170 202.9 Market 16b 16 400 350 370 400 450 430 Stock 16c 16 200 250 230 200 150 170 209.4 Market 16c 16 400 450 430 400 350 430 Stock 16d 16 200 250 230 200 150 170 204.7 Market 16d 16 400 350 370 400 450 370 Stock 23a 23 150 150 200 250 200 193.2 Market 23a 23 400 400 450 500 450 Stock 23b 23 150 150 200 250 200 197.2 Market 23b 23 400 400 350 300 350 Stock 23c 23 150 150 200 250 200 193.0 Market 23c 23 400 400 450 500 350 Stock 23d 23 150 150 200 250 200 204.3 Market 23d 23 400 400 350 300 450 Stock 24a 24 150 200 200 200 200 203.5 Market 24a 24 400 400 350 300 350 Stock 24b 24 150 200 200 200 200 196.0 Market 24b 24 400 400 450 500 450 Stock 24c 24 150 200 200 200 200 207.1 Market 24c 24 400 400 350 300 450 Stock 24d 24 150 200 200 200 200 189.5 Market 24d 24 400 400 450 500 350 Stock 25a 25 200 250 200 150 150 191.2 Market 25a 25 450 500 450 400 400 Stock 25b 25 200 250 200 150 150 201.3 Market 25b 25 450 400 450 500 500 Stock 25c 25 200 250 200 150 150 211.3 Market 25c 25 450 500 450 400 500 Stock 25d 25 200 250 200 150 150 194.6 Market 25d 25 450 400 450 500 400 Stock 26a 26 200 200 200 200 150 192.9 Market 26a 26 450 400 450 500 500 Stock 26b 26 200 200 200 200 150 189.7 Market 26b 26 450 500 450 400 400 Stock 26c 26 200 200 200 200 150 193.1 Market 26c 26 450 400 450 500 400 Stock 26d 26 200 200 200 200 150 198.6 Market 26d 26 450 500 450 400 500 Stock 33a 33 250 200 200 200 200 227.0 Market 33a 33 400 350 350 350 350 Stock 33b 33 250 200 200 200 200 235.7 Market 33b 33 400 450 450 450 450 Stock 33c 33 250 200 200 200 200 242.9 Market 33c 33 400 350 350 350 450 Stock 33d 33 250 200 200 200 200 225.5 Market 33d 33 400 450 450 450 350 Stock 34a 34 250 250 200 150 200 240.2 Market 34a 34 400 450 450 450 450 Stock 34b 34 250 250 200 150 200 231.8 Market 34b 34 400 350 350 350 350 Stock 34c 34 250 250 200 150 200 227.7 Market 34c 34 400 450 450 450 350 Stock 34d 34 250 250 200 150 200 239.3 Market 34d 34 400 350 350 350 450 Stock 35a 35 200 200 200 200 250 238.8 Market 35a 35 400 500 450 350 350 Stock 35b 35 200 200 200 200 250 240.7 Market 35b 35 400 300 350 450 450 Stock 35c 35 200 200 200 200 250 228.5 Market 35c 35 400 500 350 450 450 Stock 35d 35 200 200 200 200 250 234.9 Market 35d 35 400 300 350 450 350 Stock 36a 36 250 150 200 250 250 255.8 Market 36a 36 400 300 350 450 450 Stock 36b 36 250 150 200 250 250 255.6 Market 36b 36 400 500 450 350 350 Stock 36c 36 250 150 200 250 250 253.4 Market 36c 36 400 300 350 450 350 Stock 36d 36 250 150 200 250 250 257.1 Market 36d 36 400 500 350 450 450 Stock 45a 45 200 150 200 250 250 250 250 200 213.5 Market 45a 45 400 350 400 450 450 450 450 350 Stock 45b 45 200 150 200 250 250 250 250 200 222.0 Market 45b 45 400 450 400 350 350 350 350 450 Stock 45c 45 200 150 200 250 250 250 250 200 219.7 Market 45c 45 400 350 400 450 450 450 450 450 Stock 45d 45 200 150 200 250 250 250 250 200 221.7 Market 45d 45 400 450 400 350 350 350 350 350 Stock 46a 46 200 250 200 150 150 150 150 200 221.9 Market 46a 46 400 450 400 350 350 350 350 450 Stock 46b 46 200 250 200 150 150 150 150 200 213.5 Market 46b 46 400 350 400 450 450 450 450 350 Stock 46c 46 200 250 200 150 150 150 150 200 207.5 Market 46c 46 400 450 400 350 350 350 350 350 Stock 46d 46 200 250 200 150 150 150 150 200 212.9 Market 46d 46 400 350 400 450 450 450 450 450 Stock 47a 47 200 250 250 250 250 200 150 200 218.4 Market 47a 47 400 450 450 450 450 400 350 450 Stock 47b 47 200 250 250 250 250 200 150 200 223.8 Market 47b 47 400 350 350 350 350 400 450 350 Stock 47c 47 200 250 250 250 250 200 150 200 218.2 Market 47c 47 400 450 450 450 450 400 350 350 Stock 47d 47 200 250 250 250 250 200 150 200 217.8 Market 47d 47 400 350 350 350 350 400 450 450 Stock 48a 48 200 150 150 150 150 200 250 200 206.1 Market 48a 48 400 350 350 350 350 400 450 350 Stock 48b 48 200 150 150 150 150 200 250 200 217.3 Market 48b 48 400 450 450 450 450 400 350 450 Stock 48c 48 200 150 150 150 150 200 250 200 218.6 Market 48c 48 400 350 350 350 350 400 450 450 Stock 48d 48 200 150 150 150 150 200 250 200 211.1 Market 48d 48 400 450 450 450 450 400 350 350
1 Note: The y
To be consistent with BWW we kept the same numbering of stock patterns; therefore, as we only used a subset of patterns there are gaps in our numbering.
Each of the 63 subjects reported reference prices for 80 unique stock/market price patterns, resulting in 5040 reference point observations that we analyzed in several different ways. The average reported reference price for all subjects for each pattern appears in the last column of Table 1.
The stock and corresponding market price patterns were devised to systematically analyze interactions between stock and market effects on reference price behavior. For instance, Figure 3 displays an example involving Stock Price Patterns 1 and 2 from Table 1, which are denoted by
In each panel of Figure 3, stock patterns
Each panel in Figure 3 measures the unit impact of purchase price on the reference point under a different market scenario. In all, of the 80 unique stock/market patterns, eight orthogonal pairs can be formed to similarly measure the unit impact of
2 TableFactor pairings and results of matched‐pairs tests (N = 63)
Pair Sign test Factor Unit effect Stock Stock Market PP 1a–2b 40.27 0.40 0.000 0.927 0.000 1b–2a 43.97 0.44 0.000 0.941 0.000 1c–2d 33.05 0.33 0.000 0.911 0.000 1d–2c 43.89 0.44 0.000 0.891 0.000 7a–8b 27.90 0.28 0.000 0.792 0.000 7b–8a 29.92 0.30 0.000 0.830 0.000 7c–8d 45.11 0.45 0.000 0.939 0.000 7d–8c 43.25 0.43 0.000 0.900 0.000 Avg. 38.42 0.38 0.891 CP 11a–12b 61.24 0.61 0.000 1.000 0.000 11b–12a 46.59 0.47 0.000 0.961 0.000 11c–12d 47.21 0.47 0.000 0.964 0.000 11d–12c 40.89 0.41 0.000 0.961 0.000 15a–16b 21.29 0.35 0.000 0.894 0.000 15b–16a 22.32 0.37 0.000 0.860 0.000 15c–16d 18.49 0.31 0.000 0.864 0.000 15d–16c 20.33 0.34 0.000 0.915 0.000 Avg. 34.79 0.42 0.927 AIP 45a–46b –0.08 0.00 1.000 0.618 1.000 45b–46a 0.17 0.00 1.000 0.524 1.000 45c–46d 6.81 0.14 0.631 0.690 0.329 45d–46c 14.19 0.28 0.001 0.871 0.000 47a–48b 1.11 0.02 1.000 0.553 1.000 47b–48a 17.71 0.35 0.000 0.857 0.000 47c–48d 7.03 0.14 0.277 0.742 0.056 47d–48c –0.76 –0.02 1.000 0.455 1.000 Avg. 5.77 0.12 0.664 HP 23a–24b –2.78 –0.06 1.000 0.400 1.000 23b–24a –6.28 –0.13 1.000 0.333 0.364 23c–24d 3.48 0.07 1.000 0.545 1.000 23d–24c –2.83 –0.06 1.000 0.400 1.000 25a–26b 1.51 0.03 1.000 0.543 1.000 25b–26a 8.41 0.17 0.755 0.611 1.000 25c–26d 12.68 0.25 0.335 0.585 1.000 25d–26c 1.41 0.03 1.000 0.552 1.000 Avg. 1.95 0.04 0.496 LP 33a–34b –4.79 –0.10 1.000 0.421 1.000 33b–34a –4.48 –0.09 1.000 0.371 1.000 33c–34d 3.52 0.07 1.000 0.625 1.000 33d–34c –2.17 –0.04 1.000 0.412 1.000 35a–36b –16.78 –0.34 0.001 0.171 0.000 35b–36a –15.06 –0.30 0.005 0.205 0.001 35c–36d –28.54 –0.57 0.000 0.137 0.000 35d–36c –18.56 –0.37 0.000 0.152 0.000 Avg. –10.86 –0.22 0.312
2 Note: This table shows the price pattern pairings used to isolate stock price factors, and results of paired‐sample analyses consisting of a t‐test of different means and a matched‐pair sign test. Price patterns are designed to isolate the effect of each stock price factor on the reference price, with eight pairings designed for each factor: purchase price (PP), current price (CP), average intermediate price (AIP), high price (HP), and low price (LP). Reported p‐values are two‐tailed and are Bonferroni adjusted to take into account multiple pairwise comparisons for each factor. The sample proportion P̂ refers to the fraction of subjects with positive values of (R
For each pair, we perform a matched‐pair sign test to test the significance of results for each row in the table, similar to BWW. In performing their matched‐pairs sign tests, BWW use the definitional formula for
For
-
Purchase price (PP): We find an overall average unit effect of 0.38 for
-
Current price (CP): For
-
Average intermediate price (AIP): For
-
High price (HP): We find HP to be largely noninfluential. The overall average unit effect is only 0.04, and none of the orthogonal pairs involving
-
Low price (LP):
Overall, these results suggest that observed differences in unit effect across treatments can be attributed to market context. In Table 3 we formally test for differences in unit effect across market patterns using a two‐stage process. First, in Panel A we perform homogeneity tests on the mean difference unit effect for each stock factor using a one‐way analysis of variance (ANOVA) test. For each price factor, the treatments are split into two subgroups for analysis based on the stock pairings, resulting in four treatments for each subgroup. Then, for any subgroup found to be significantly heterogeneous at the 10% level, in Panel B we perform a post hoc analysis of pairwise differences in mean unit effect for all possible pairwise combinations of treatments within each subgroup that advances to this stage. The post hoc test is performed at the 5% significance level. Panel B can be viewed as a multiple‐treatment framework; therefore, we Bonferroni‐correct the p‐values to control for the familywise error rate. In Panel B we report both single‐test (unadjusted) and Bonferroni‐corrected p‐values.
3 TableImpact of market pattern on unit effect
Analysis Stock No. Factor subgroup pairing of tests PP A 1 vs. 2 4 1.145 0.331 B 7 vs. 8 4 2.568 0.055 CP A 11 vs. 12 4 2.601 0.053 B 15 vs. 16 4 0.191 0.902 AIP A 45 vs. 46 4 2.786 0.041 B 47 vs. 48 4 5.267 0.002 HP A 23 vs. 24 4 0.970 0.408 B 25 vs. 26 4 1.369 0.253 LP A 33 vs. 34 4 1.230 0.299 B 35 vs. 36 4 1.930 0.125
3 TableImpact of market pattern on unit effect
PP B 7a–8b vs. 7b–8a –0.02 0.664 1.000 7a–8b vs. 7c–8d –0.17 0.010 0.058 7a–8b vs. 7d–8c –0.15 0.018 0.108 7b–8a vs. 7c–8d –0.15 0.030 0.179 7b–8a vs. 7d–8c –0.13 0.042 0.252 7c–8d vs. 7d–8c 0.02 0.675 1.000 CP A 11a–12b vs. 11b–12a 0.15 0.011 0.065 11a–12b vs. 11c–12d 0.14 0.012 0.069 11a–12b vs. 11d–12c 0.20 0.001 0.004 11b–12a vs. 11c–12d –0.01 0.919 1.000 11b–12a vs. 11d–12c 0.06 0.272 1.000 11c–12d vs. 11d–12c 0.06 0.116 0.693 AIP A 45a–46b vs. 45b–46a –0.01 0.961 1.000 45a–46b vs. 45c–46d –0.13 0.196 1.000 45a–46b vs. 45d–46c –0.29 0.005 0.032 45b–46a vs. 45c–46d –0.13 0.324 1.000 45b–46a vs. 45d–46c –0.28 0.008 0.047 45c–46d vs. 45d–46c –0.15 0.124 0.743 AIP B 47a–48b vs. 47b–48a –0.33 0.003 0.016 47a–48b vs. 47c–48d –0.12 0.296 1.000 47a–48b vs. 47d–48c 0.04 0.700 1.000 47b–48a vs. 47c–48d 0.21 0.023 0.141 47b–48a vs. 47d–48c 0.37 0.000 0.001 47c–48d vs. 47d–48c 0.16 0.048 0.289
3 Note: This table displays results of subgroup analyses to investigate whether differences in the unit effects in Table 2 can be attributed to differing market background information. In Panel A, one‐way analysis of variance (ANOVA) F‐tests of homogeneity are performed on treatment subgroups selected to differ only with respect to market pattern. In Panel B, post hoc analysis is performed on subgroups found to be significantly heterogeneous at α =.10. Post hoc analysis consists of paired‐difference t‐tests of differences in mean unit effects between all possible within‐subgroup treatment pairs. The p‐values reported in Panel B include both single‐test and Bonferroni‐adjusted values. See Table 2 for factor definitions.
In Panel A of Table 3 we find that the following 4 of 10 subgroups exhibit sufficient heterogeneity to advance to the post hoc stage:
In analyzing the average unit effect in Tables 2 and 3, we do not condition the results on the market; therefore, our results can be compared to the unconditional impact measured by BWW who do not include market information in their experiment. When taken together, our results are remarkably consistent with BWW for most of the stock price factors. Notably, our overall average unit effect across all scenarios for all five factors combined is equal to 0.74, compared to an overall average of 0.75 for BWW. In Section 5 we decompose BWW's unconditional measures by examining stock and market interaction effects to provide a more nuanced explanation of reference point formation.
Following BWW, we analyze the impact of relevant factors by performing a regression of the reference prices reported by subjects on relevant factors in a combined model containing data from all of the paired comparisons. Whereas BWW consider only the five stock‐related factors discussed earlier, we include market‐related factors as additional independent variables. Results appear in Table 4. Significance of coefficients is examined at the 5% level. For comparison purposes, we include BWW's findings in Table 4. As in BWW, standard errors are clustered by subject to remove correlation bias.
4 TableRegression of Rk on stock‐ and market‐related factors (N = 5040)
BWW Model Model Model Model Model Model Model ( 1 2 3 4 5 6 7 Intercept 15.200003 57.530004 23.22 26.86 15.89 22.83 19.23 7.88 Stock PPstk 0.500004 0.380004 0.370004 0.380004 0.350004 0.370004 0.360004 0.340004 CPstk 0.270004 0.430004 0.450004 0.430004 0.500004 0.450004 0.420004 0.440004 AIPstk 0.130004 0.02 0.03 0.060002 0.04 0.03 0.120004 0.110004 HPstk 0.070004 0.00 0.02 0.01 0.02 0.02 0.03 0.08 LPstk −0.040002 −0.050002 −0.060002 −0.060002 −0.060003 −0.060002 −0.03 −0.05 LASTLEGstk — — — 0.030002 — — — — TRENDstk — — — — −0.10 — — — UP_DOWNstk — — — — — — −5.040003 −4.350002 DOWN_UPstk — — — — — — 6.350004 4.410003 Market PPmkt — — 0.05 0.04 0.03 0.05 0.03 0.04 CPmkt — — 0.060004 0.02 0.080004 0.060004 0.060004 0.02 AIPmkt — — −0.050003 −0.02 −0.060004 −0.050003 −0.050003 −0.02 HPmkt — — −0.01 0.01 0.00 0.00 0.00 −0.01 LPmkt — — 0.01 0.00 0.02 0.01 0.00 0.02 LASTLEGmkt — — — 0.030004 — — — 0.040004 TRENDmkt — — — — −0.130004 — — — Covariation BETA — — — — — −0.31 — — POS_BETA — — — — — — — −2.700002 NEG_BETA — — — — — — — −1.92 POS_BETA × LASTLEGmkt — — — — — — — 0.01 NEG_BETA × LASTLEGmkt — — — — — — — −0.050004 Adj. R2 na 0.271 0.280 0.282 0.281 0.280 0.282 0.286
- 4 Note: Baucells et al. (2011; BWW) results from their five‐factor model that includes only stock factors (defined in Table 2). LASTLEG denotes the magnitude of price change from the last inflection point in the visual pattern, and TREND denotes the slope of a linear best fit line fitted to the price sequence. UP_DOWN and DOWN_UP are indicator variables denoting patterns that follow strictly up/down or down/up shapes, respectively. BETA is the conventional beta measure computed from the returns implied by stock and market patterns, and POS_BETA and NEG_BETA are indicator variables denoting observations in the top and bottom beta terciles, respectively. Standard errors are clustered by subject.
- 5 * p < 0.10;
- 6 ** p < 0.05;
- 7 *** p < 0.01.
In Table 4, we first perform a "naı̈ve" regression (Model 1) using the same five stock‐related factors used by BWW. In comparing our results to BWW, we note that BWW obtain significance for all five stock‐related factors, whereas we obtain significance for only three factors: PP, CP, and LP. The difference in results can be explained by the fact that BWW used only stock price information to form their reference price, whereas our subjects used additional market information. We suggest that the presence of market information led investors to focus less on intermediate stock price factors, consistent with the divided attention hypothesis (H2).
Our intercept of 57.53 is significantly higher than BWW's intercept of 15.20. We explain this difference by noting that even though it is the same regression equation, subjects in the two studies had different information when they formed their reference points. Our subjects had additional market information that BWW subjects did not. We contend that our intercept is higher because it absorbs the explanatory power associated with market‐related factors, which represent omitted variables in our Model 1. BWW's subjects did not have market information when forming their reference prices, so those are not "omitted variables" in BWW. This argument is reinforced by the observation that when we add the missing market factors in our subsequent models, the intercept drops to a level that is commensurate with what BWW find using the five stock variables. BWW attribute their intercept to the possibility that subjects may haved added a built‐in profit, which is a viable interpretation for both models. In Model 1 our coefficients on PP and CP are 0.38 and 0.43, respectively, compared to BWW's coefficients of 0.50 and 0.27.
In Model 2 we add five market‐related price factors:
In Models 3 and 4, respectively, we add terms for both the stock and the market related to short‐ and long‐term price trends. In Model 3 we add a factor called LASTLEG to capture the current short‐term price trend as measured by the magnitude of price change from the last inflection point in the visual pattern. In Model 4 we add a factor called TREND to capture the long‐term overall linear price trend, defined by the slope of a best‐fit line computed for each price sequence plotted as a function of time using ordinary least squares. We find that for LASTLEG, the coefficient is positive and significant for both the stock and the market, indicating end‐anchoring effects (H8) for both charts, although the magnitude of the coefficient is close to 0, equaling 0.03 in both cases. This is consistent with short‐term trend continuation beliefs for both the stock and the market. It is also consistent with the GM explanation that reference points are influenced by feelings of investor optimism or pessimism gleaned from viewing the stock or market chart (H5). For TREND, we find that the coefficient is significant only for the market pattern, with a negative coefficient of −0.13. This contradicts both H5 and H8 when market direction is defined by the longer term linear trend as opposed to last price move, suggesting that perhaps this overall result is driven by stock/market interaction effects, which we explore in subsequent analyses that partition on stock and market states.
In Model 5 we add BETA as a measure of covariation, defined as the slope of the characteristic line obtained by regressing the stock return on the market return using returns implied by each pair of stock and market price sequences. BETA is not significant in Model 5. In Model 6 we add indicator variables
Finally, in Model 7 we add two indicator variables to represent covariation effects based on positive or negative beta; these variables represent the top and bottom terciles of beta and are named
Overall, for the models considered we find that the significance of market factors varies depending on which measures of stock and market trend are included in the model. At the same time, we find that the stock's purchase price and current price remain consistently significant across all model specifications with fairly stable coefficient values of approximately 0.37 for
To further disentangle the stock and market effects, we perform regressions on indicator variables corresponding to different combinations of up/down price scenarios. We examine both one‐way effects (stock or market direction considered separately) and two‐way effects (combined stock and market directions). We include the five stock price factors in the regressions and add
5 TableRegression of Rk on stock and market states
One‐way analysis Two‐way analysis Coeff. Intercept β0 37.180004 36.740004 39.370004 38.400004 Indicator variables STKUP β1 –4.12 –3.64 − − STKDN β2 3.16 3.18 − − MKTUP β3 4.940004 –2.07 − − MKTDN β4 –2.690003 –4.720003 − − STKUP_MKTUP β5 − − 3.16 0.53 STKUP_MKTDN β6 − − –4.960003 –1.10 STKDN_MKTUP β7 − − 5.410004 0.80 STKDN_MKTDN β8 − − –2.36 –5.490003 Stock price factors PPstk β9 0.290004 0.300004 0.340004 0.380004 CPstk β10 0.490004 0.480004 0.430004 0.380004 AIPstk β11 0.110004 0.110004 0.110004 0.120004 HPstk β12 0.01 0.04 0.02 0.02 LPstk β13 –0.02 −0.04 −0.03 −0.02 Control variables UP_DOWNstk β14 –5.070003 –4.470003 –5.560003 –4.940003 DOWN_UPstk β15 5.650003 6.380003 6.080003 7.240003 BETA β16 –0.14 –0.19 –0.13 0.03 N 5040 5040 5040 5040 Adj. R2 0.281 0.274 0.280 0.275
- 8 Note: In this table we regress the reference point (Rk) on the five Baucells et al. (2011; BWW) stock factors (defined in Table 2) plus indicator variables to represent different combinations of up/down price scenarios using three criteria: stock price direction is based on positive or negative capital gains (GAIN), and market price direction is based on positive/negative price trend (TREND) or positive/negative last leg price direction (LASTLEG). Additional variables are included to control for the impact of the visual pattern on investor satisfaction and for covariation effects. UP_DOWN and DOWN_UP are indicator variables denoting patterns that follow strictly up/down or down/up shapes, respectively, and BETA is the conventional beta measure computed from the returns implied by stock and market patterns. STKUP and STKDN are dummy variables indicating up‐ and down‐stock states, respectively, and MKTUP and MKTDN are dummy variables indicating up‐ and down‐market states. The regression coefficients are used to perform hypothesis tests of stock/market interaction effects. The one‐way analysis model corresponds to Equation (
2 ), and the two‐way analysis model corresponds to Equation (3 ). Standard errors are clustered by subject. - 9 * p < 0.10;
- 10 ** p < 0.05;
- 11 *** p < 0.01.
- 6 TableRegression of Ak on stock and market states
One‐way analysis Two‐way analysis Coeff. Intercept ß0 ‐ ‐ 2.0640002 1.687 Indicator variables STKUP ß1 1.225 1.208 ‐ ‐ STKDN ß2 0.788 0.777 ‐ ‐ MKTUP ß3 0.1410004 0.005 ‐ ‐ MKTDN ß4 –0.028 –0.0700002 ‐ ‐ STKUP_MKTUP ß5 ‐ ‐ 0.1670003 0.041 STKUP_MKTDN ß6 ‐ ‐ –0.014 0.031 STKDN_MKTUP ß7 ‐ ‐ 0.1210003 –0.039 STKDN_MKTDN ß8 ‐ ‐ –0.036 –0.1660004 Stock price factors PPstk ß9 –0.0080004 –0.0080004 –0.0130004 –0.0110004 CPstk ß10 0.0040002 0.0040002 0.0080004 –0.0080004 AIPstk ß11 0.000 0.001 –0.005 –0.003 HPstk ß12 0.001 0.0010002 0.0010002 0.0010002 LPstk ß13 –0.001 –0.0020003 –0.001 –0.0020003 Control variables UP_DOWNstk ß14 –0.113 –0.110 0.022 –0.019 DOWN_UPstk ß15 –0.006 0.014 –0.139 –0.083 BETA ß16 –0.001 –0.001 0.001 0.006 N 3780 3780 3780 3780 Adj. R2 0.474 0.469 0.398 0.393
- 12 Note: In this table we regress reference point adaptation (A
k ) on the five Baucells et al. (2011; BWW) stock factors (defined in Table 2) plus indicator variables to represent different combinations of up/down price scenarios using three criteria: stock price direction is based on positive or negative capital gains (GAIN), and market price direction is based on positive/negative price trend (TREND) or positive/negative last leg price direction (LASTLEG). Additional variables are included to control for the impact of the visual pattern on investor satisfaction and for covariation effects. UP_DOWN and DOWN_UP are indicator variables denoting patterns that follow strictly up/down or down/up shapes, respectively, and BETA is the conventional beta measure computed from the returns implied by stock and market patterns. STKUP and STKDN are dummy variables indicating up‐ and down‐stock states, respectively, and MKTUP and MKTDN are dummy variables indicating up‐ and down‐market states. The regression coefficients are used to perform hypothesis tests of stock/market interaction effects. The one‐way analysis model corresponds to Equation (4 ), and the two‐way analysis model corresponds to Equation (5 ). Note that 1260 observations were lost due to undefined Ak resulting from equal current and purchase stock prices. Standard errors are clustered by subject. - 13 * p < 0.10;
- 14 ** p < 0.05;
- 15 *** p < 0.01.
For Table 5, the regression equations for one‐way and two‐way analyses are, respectively:
- 2
- 3
For Table 6, the regression equations for one‐way and two‐way analyses are, respectively:
- 4
- 5
In implementing these regressions, for the focal stock variable we define the price state in terms of capital gains and losses, computed as (
In Table 5 we observe that for the one‐way analysis, when market direction is defined by LASTLEG the two significant states are MKTUP and MKTDN with observed coefficients of 4.94 and −2.69, respectively. Both of the stock state indicators are nonsignificant. This suggests that end‐anchor effects are stronger for the contextual market variable than they are for the focal stock variable. We suggest that this may be because the focal stock variable is driven by a combination of hedonic maximization considerations and end‐anchoring effects, such that these may be competing or offsetting effects for some chart patterns, whereas market direction arguably does not entail the same type of hedonic consequences that may pertain to own‐stock gains and losses. The observed signs for the market‐related coefficients are consistent with anchoring to the market (H7, H8) or alternatively by optimism/pessimism (H5). We formally test these conjectures in subsequent analyses.
When market direction is defined by TREND, for the one‐way analysis the only state variable that is significant in the GAIN/TREND partition is MKTDN with a negative coefficient of −4.72. We see that for the two‐way analysis this result is reinforced where the only combined market state that is significant is
For the two‐way analysis in the GAIN/LASTLEG partition, we observe that the
In Table 6, the dependent variable is
In the GAIN/TREND partition, for the one‐way analysis only the MKTDN state is significant with a negative coefficient of −0.70. This implies there is less adaptation when investors are focusing on long‐term market trend. It is reinforced by the two‐way analysis where only the
The regressions described earlier are used to formulate hypothesis tests to examine stock and market interaction effects more formally. To guide our interpretation of results we first develop the sign predictions shown in Table 7.
7 TablePredicted signs for hypothesis tests
Market context effect based on Market context effect based on optimism/pessimism or anchoring0002 attention in up vs. down markets Stock Market Combined Stock Market Combined effect effect effect effect effect effect Coeff. eq. eq. Panel A: Analysis of STKUP versus STKDN conditioned on market states (1) ALL MKT S ↑ Impact β1 (2) (4) ↑ ↑ ↑ ↑ S ↓ Impact β2 (2) (4) ↑ ↓ ↑ ↓ Predicted sign (β1–β2) (2) (4) 0 (+) 0 (+) (2) MKTUP S ↑ M ↑ Impact β5 (3) (5) ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ S ↓ M ↑ Impact β7 (3) (5) ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↓ ↑ 0 0 Predicted sign (β5–β7) (3) (5) 0 (+) 0 (+) 0 (+) 0 (+) (+) 0 (+) (+) (3) MKTDN S ↑ M ↓ Impact β6 (3) (5) ↑ ↑ ↓ ↓ 0 0 ↑ ↑ ↓ ↓ 0 0 S ↓ M ↓ Impact β8 (3) (5) ↑ ↓ ↓ ↑ 0 0 ↑ ↓ ↑ ↓ ↑ ↓ Predicted sign (β6–β8) (3) (5) 0 (+) 0 (–) 0 0 0 (+) (–) 0 (–) (+) Panel B: Analysis of MKTUP versus MKTDN conditioned on stock states (1) ALL STK M ↑ Impact β3 (2) (4) ↑ 0 0 ↑ M ↓ Impact β4 (2) (4) ↓ 0 0 ↓ Predicted sign (β3–β4) (2) (4) (+) 0 0 (+) (2) STKUP S ↑ M ↑ Impact β5 (3) (5) ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ S ↑ M ↓ Impact β6 (3) (5) ↑ ↑ ↓ ↓ 0 0 ↑ ↑ ↓ ↓ 0 0 Predicted sign (β5–β6) (3) (5) 0 0 (+) (+) (+) (+) 0 0 (+) (+) (+) (+) (3) STKDN S ↓ M ↑ Impact β7 (3) (5) ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↓ ↑ 0 0 S ↓ M ↓ Impact β8 (3) (5) ↑ ↓ ↓ ↑ 0 0 ↑ ↓ ↑ ↓ ↑ ↓ Predicted sign (β7–β8) (3) (5) 0 0 (+) (–) (+) (–) 0 0 (–) (+) (–) (+)
- 16 Note: This table reports the derivation of predicted signs for hypothesis tests to be performed on Equations (
2 )–(5 ). MKTUP and MKTDN are dummy variables indicating up‐ and down‐market states, respectively, and ALL_MKT is a dummy variable indicating the combined set of observations. The predicted stock effect is based on prospect theory with a null hypothesis that the focal stock effect exhibits greater adaptation in the gain versus loss domain. Two contrasting mechanisms of market context effect are considered: optimism/pessimism and attention. For optimism/pessimism, we hypothesize that up‐market states lead to higher reference prices relative to down‐market states due to feelings of optimism or pessimism as suggested by the Gollier and Muermann (2010) model. For attention, we hypothesize that adaptation is greater for up‐ versus down‐market states due to greater attention as suggested by the asymmetric ostrich effect (Karlsson et al., 2009). Focal and contextual effects may be reinforcing or offsetting, resulting in a combined effect that may be positive, negative, or neutral. - 17 a For this table, identical results would obtain if market context effects were based on optimism/pessimism or anchoring to the market, as either mechanism would be implemented by moving the reference price in the market direction. This is not a general result but depends on how market direction is defined among other assumptions. In our empirical tests we contrast differing definitions of market direction based on TREND or LASTLEG.
Numerous studies document asymmetric adaptation in the gain versus loss domains, and for the focal stock effect we use this hypothesis as a base assumption for purposes of developing our sign predictions. Because the stock direction is defined by paper gains and losses,
To analyze contextual effects, we add market effects that are theorized two ways: (
Focal and contextual effects may be reinforcing or offsetting, resulting in a combined effect that may be positive, negative, or neutral. In our modeling framework the hypothesized signs in the GM framework are identical to what would be predicted under an assumption of anchoring to the market, as each mechanism implies the reference point moves in the market direction. This is not a general result but is a convenient factor when interpreting our regressions. The empirical question of what market effects are actually observed plausibly depends on the definition of market direction. In our empirical tests, the GAIN/LASTLEG and GAIN/TREND indicator variables allow us to test our hypotheses under the two alternate definitions of market direction.
In Table 8 we perform hypothesis tests on
8 TableResults of hypothesis tests
Dependent variable = Dependent variable = Predicted sign Predicted sign Null per market effect Observed coeff. difference0002 per market effect Observed coeff. difference0002 hypoth. eq. eq. Opt/Anchor Attn Opt/Anch Attn Panel A: Test condition: Dependent variable is higher for STKUP versus STKDN (1) ALL MKT ß1–ß2 = 0 (2) (4) 0 0 –7.28 –6.81 (+) (+) 0.440003 0.430003 (0.202) (0.233) (0.023) (0.019) (2) MKTUP ß5–ß7 = 0 (3) (5) 0 (+) –2.25 –0.27 (+) (+) 0.05 0.08 (0.289) (0.908) (0.377) (0.118) (3) MKTDN ß6–ß8 = 0 (3) (5) 0 (–) –2.60 4.390003 0 (+) 0.02 0.200005 (0.242) (0.048) (0.667) (0.000) Panel B: Test condition: Dependent variable is higher for MKTUP versus MKTDN (1) ALL STK ß3–ß4 = 0 (2) (4) (+) 0 7.640005 2.650004 0 (+) 0.170005 0.080004 (0.000) (0.008) (0.000) (0.004) (2) STKUP ß5–ß6 = 0 (3) (5) (+) (+) 8.120005 1.62 (+) (+) 0.180005 0.01 (0.000) (0.186) (0.000) (0.698) (3) STKDN ß7–ß8 = 0 (3) (5) (+) (–) 7.770005 6.280005 (–) (+) 0.160005 0.130005 (0.000) (0.000) (0.000) (0.000)
- 18 Note: This table reports the results of hypothesis tests performed on Equations (
2 )–(5 ) to analyze stock/market interaction effects. MKTUP and MKTDN are dummy variables indicating up‐ and down‐market states, respectively, and ALL_MKT is a dummy variable indicating the combined set of observations. Row 1 in both panels presents one‐way analyses of pure stock or market effects, and Rows 2 and 3 present two‐way analyses. Predicted signs are from Table 7 and are based on three alternative theories for the market context effect: optimism/pessimism ("Opt"), anchoring to the market ("Anchor"), and attention ("Attn"). Note that optimism/pessimism and anchoring to the market produce identical sign forecasts in the specific framework of this study. Standard errors are clustered by subject. p‐values are presented in parentheses. - 19 a The test is two‐tailed. Positive coefficient difference indicates right‐tail significance; negative coefficient difference indicates left‐tail significance.
- 20 * p < 0.10;
- 21 ** p < 0.05;
- 22 *** p < 0.01.
Row 1 in Panel A of Table 8 indicates that when market states are combined, the unconditional stock effect is exactly as hypothesized for each dependent variable, and it supports the prospect theory explanation of asymmetric adaptation in gain versus loss domains (H4). However, Rows 2 and 3 reveal that this effect is moderated when conditioned on market direction. It obtains only in the down‐market state and when market direction is defined by TREND as opposed to LASTLEG. Further insight is obtained from Tables 5 and 6, which indicate that for both dependent variables, the result is driven by
For
Focusing on
Row 1 in Panel B of Table 8 indicates that the pure stock effect is exactly as hypothesized for each dependent variable whether the predicted market effect is through the mechanism of optimism/pessimism (H5) or by attentional factors (H3), and it supports the prospect theory explanation of asymmetric adaptation in gain versus loss domains (H4). However, Rows 2 and 3 reveal that this effect is moderated when conditioned on stock states.
In Panel B of Table 8, we observe that reference point adaptation is uniformly higher in up‐ versus down‐market states for all partitions except one: the GAIN/TREND partition in the STKUP state. The coefficient spread for this test is (
Turning to the GAIN/LASTLEG partition for which all hypothesis tests in Table 8 are positive and significant, an analysis of the coefficients in Table 5 shows an interesting pattern when analyzing the results for
Examining the coefficients for
To gain additional intuition and further sort out patterns of stock and market influences on reference prices, we provide graphical analysis of our results in Figures 4 and 5. These graphs provide deeper insight and aid in visualizing stock and market interaction effects in a convenient and novel manner.
The extent of adaptation for a given individual may depend on intermediate stock and market price movements, and such factors may affect different individuals in different ways. However, the same individual may exhibit patterns of consistent behavior according to the market state and/or based on whether the stock is in a capital gain (
The results in Figure 4 indicate asymmetric adaptation in both up and down markets, with a slightly stronger effect when the market trends upward. In up‐market scenarios, 57 subjects (90%) exhibit this behavior versus 49 subjects (78%) in down‐market scenarios. A reverse asymmetric adaptation effect is observed for 6 subjects (10%) in up‐market scenarios and for 13 subjects (21%) in down‐market scenarios.
In Figure 5, we slice the data in a different manner and analyze within‐subject behavior along the dimensions of up versus down markets, where up and down markets are defined by the sign of
In the gain domain positive adaptation implies an increase in the reference price, whereas in the loss domain positive adaptation implies a decrease in the reference price. This is because the denominator in the definition equation of adaptation is negative in the loss domain and positive in the gain domain. In Panel (b) of Figure 5, an increase in the reference price corresponds to a rightward (in down markets) or upward (in up markets) shift of data points on the graph. But in Panel (a), an increase in the reference price corresponds to a leftward (in down markets) or downward (in up markets) shift of data points on the graph. The gain and loss regions in the two panels are indicated by shading.
Figure 5 offers interesting insights. First, the inner box depicts individuals who adjust their reference point less than halfway, which indicates that they are focusing more on the purchase price than the current price. This happens mostly in the loss domain. Relatively few individuals in the gain domain exhibit this behavior. Second, points in the upper right quadrant represent individuals who systematically adapt positively in both up and down markets, and anything in the lower left quadrant represents individuals who systematically adapt negatively in both up and down markets. There is virtually no negative adaptation in the gain domain; but in the gain domain negative adaptation means the reference point is lower than
The region outside of the inner box represents adaptation greater than 0.5 suggesting that an individual is focusing more on the current price than the purchase price. This happens frequently in the gain domain but infrequently in the loss domain, as would be expected as greater adaptation in the loss domain approaches capital loss territory with respect to the purchase price as adaptation approaches 1. The region outside of the outer box represents adaptation greater than 1, which occurs frequently in the gain domain but rarely in the loss domain. This is intuitive, as in the loss domain this implies a capital loss relative to the purchase price. These types of observations are not evident when all up/down scenarios are lumped together, but these observations motivate the partitioning of the data.
In the gain domain, the data points in the first quadrant that lie outside the larger box represent overadaptation (
In this article, we develop an experimental framework for analyzing the effect of market context on reference point formation, synthesizing and extending previous studies by BWW and GM. By presenting market information additionally to the stock price path, we explore the influence of market contextual information on reference point formation and updating for stock investments given different price path scenarios. The results support our overall hypothesis that market context matters and information about the market influences the formation and updating of reference points in some systematic ways.
Based on theories in the literature, we create specific hypotheses on how market contextual information may affect the reference point dynamics of individual stocks. Through our extended experimental framework, we investigate and analyze how reference point adaptation depends on market context. In addition, we develop a novel method of graphical portrayal that helps visualize behavioral effects on reference point formation and provides additional insights.
We note the following limitations of our study. Like numerous other studies that use artificial charts, our results may be affected by round‐number bias and by the use of short chart lengths in our stock and market patterns, which result in less realistic measures for variables like beta. However, we believe the benefit of retaining these features from the BWW study for comparability outweigh the disadvantages of trying to correct for these effects. In addition, by originating the stock and market patterns at different price points, we do not control for differences in the rate of return or beta across stock and market sequences. Finally, because we do not include a control group of subjects to view just the stock pattern without the market information as in BWW, comparing our results with those of BWW does not constitute a formal control.
Although our study does not consider every possible factor that may influence reference point formation in different market states, we believe it is a step in that direction. Our methodology provides a rich framework for analyzing reference price formation that will be a useful platform for performing future research in this area. Possible areas for future inquiry may include, for example, an examination of heterogeneous subject types (e.g., with respect to momentum vs. contrarian beliefs or exhibiting reference point formation consistent with different investment styles such as growth vs. value) to determine whether subject behavior changes under different economic states. Another area that may benefit from further investigation is using our combined framework to further explore covariation effects or to examine effects related to higher moments such as skewness or coskewness (e.g., Ang et al., 2006; Bajtelsmit et al., 2015).
The authors greatly appreciate comments and help from the editor, anonymous reviewers, and participants at the Academy of Behavioral Finance & Economics Annual Meeting, Society for Experimental Finance Annual Meeting, American Society of Business and Behavioral Sciences Annual Meeting, Eastern Finance Association Annual Meeting, Midwest Finance Association Annual Meeting, and Southwestern Finance Association Annual Meeting.
By Tianyang Wang; Robert G. Schwebach and Sriram V. Villupuram
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