numerical information format and investment decisions: implications for the disposition effect and...

This article was downloaded by: [University of Bath]On: 04 October 2014, At: 03:20Publisher: RoutledgeInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UK

Journal of Behavioral FinancePublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/hbhf20

Numerical Information Format and InvestmentDecisions: Implications for the Disposition Effect andthe Status Quo BiasEnrico Rubaltelli , Sandro Rubichi , Lucia Savadori , Marcello Tedeschi & Riccardo FerrettiPublished online: 07 Jun 2010.

To cite this article: Enrico Rubaltelli , Sandro Rubichi , Lucia Savadori , Marcello Tedeschi & Riccardo Ferretti (2005)Numerical Information Format and Investment Decisions: Implications for the Disposition Effect and the Status Quo Bias,Journal of Behavioral Finance, 6:1, 19-26, DOI: 10.1207/s15427579jpfm0601_4

To link to this article: http://dx.doi.org/10.1207/s15427579jpfm0601_4

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) containedin the publications on our platform. However, Taylor & Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of theContent. Any opinions and views expressed in this publication are the opinions and views of the authors, andare not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon andshould be independently verified with primary sources of information. Taylor and Francis shall not be liable forany losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoeveror howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use ofthe Content.

This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

Numerical Information Format and Investment Decisions:Implications for the Disposition Effect and the Status Quo Bias

Enrico Rubaltelli, Sandro Rubichi, Lucia Savadori,Marcello Tedeschi and Riccardo Ferretti

Investment decisions are very difficult because they involve money and can impact ourquality of life. According to the axioms of rationality, different but equivalent informa-tion formats should not affect investment strategies. The authors perform two experi-ments here, and find evidence of a strong absolute magnitude effect on investment de-cisions. In Experiment 1, participants (students) chose to sell a losing fund more oftenwhen returns were expressed as a percentage of variation between the buying valueand the actual value (e.g., 24%) than when they were expressed as a monetary differ-ence between the buying price and the actual price (e.g., $0.24). In the context of theexperiment, the percentage format decreased the disposition effect significantly. Fur-thermore, describing the stock returns as ratios (e.g., ¼) increased the tendency to-ward the status quo bias. In Experiment 2, the authors showed that the absolute mag-nitude of the numbers shaped participants’ satisfaction with fund returns, and wasresponsible for the different choices of investment strategies.

An increasing number of people are actively invest-ing in stock markets, and many are basing their invest-ment decisions on descriptive information fromsources such as banks, financial advisors, the mass me-dia, or friends. But as the number of people who are in-vesting increases, so inevitably does the number of“naive investors.” According to rational principles ofeconomic theory, the way information is presentedshould not affect investment decisions. Nevertheless, awell known finding in decision making research showsthat logically equivalent information formats can leadto different choices.

The classical framing effect (Tversky andKahneman [1981]) has a long history in the psy-chology of decision making. In the study known asthe “Asian disease problem,” different framing oflogically equivalent information (expressed eitheras number of lives saved or number of lives lost)is seen to induce different choices. Increasing thedifficulty of information processing, such as pre-senting individuals with fractions that are difficult

to compute (e.g., 856/963), has been found toincrease the frequency of preference reversals(Johnson, Payne, and Bettman [1988]).

Other studies have specifically investigated the ef-fect of different numerical information formats.Bayesian reasoning can be improved by representinginformation in frequency formats rather than in prob-abilities (Gigerenzer and Hoffrage [1995, 1999]).Stone, Yates, and Parker [1994] found that individu-als were willing to pay more for improved tires whenthey were described in terms of ratios (half the acci-dent rate of standard tires), than when they were de-scribed in an incidence rate format (a 0.0000030probability of serious injury).

Finally, Halpern, Blackman, and Salzman [1989]found that displaying information in a relative formatleads to less risky behavior. They studied the percep-tion of risk associated with the use of oral contracep-tives. They presented the same probability in six dif-ferent formats: natural frequencies framed in apositive format (99,991.7 out of 100,000 will notdie), percentages (a 0.0083% probability of dying),frequencies (1 in 12,000 die), natural frequencies (8.3in 100,000 die), ratios (4.15 times greater risk ofdeath), and percentages (415% greater risk of death).The last two formats differ from the previous four inthat they do not convey any base rate information.According to Halpern, Blackman, and Salzman[1989], base rate information formats (1 in 12,000will die) provide an expected value, while relative in-formation formats (e.g., twice as many will die) giveno information about the expected frequency (twiceas many as what number?). When a base rate was

The Journal of Behavioral Finance2005, Vol. 6, No. 1, 19–26

Copyright © 2005 byThe Institute of Behavioral Finance

19

Enrico Rubaltelli, Sandro Rubichi, Marcello Tedeschi, andRiccardo Ferretti are all affiliated with the Department of Social,Cognitive and Quantitative Sciences at the University of Modenaand Reggio Emilia. Enrico Rubaltelli is a Ph.D. candidate, SandroRubichi and Marcello Tedeschi are associate professors, andRiccardo Ferretti is a full professor.

Lucia Savadori is a researcher in the Department of Cognitiveand Educational Sciences at the University of Trento.

Requests for reprints should be sent to Enrico Rubaltelli, Depart-ment of Social, Cognitive and Quantitative Sciences, University ofModena and Reggio Emilia, via Gilioli Valle 9, Y2100, ReggioEmilia, Italy. Email: rubaltelli.enrico@unimore.it

Dow

nloa

ded

by [

Uni

vers

ity o

f B

ath]

at 0

3:20

04

Oct

ober

201

4

provided, these events were perceived as less likely tooccur (Halpern, Blackman, and Salzman [1989]).

Halpern, Blackman, and Salzman [1989] also foundthat respondents ignore the format in which the numer-ical information is provided and make safety determi-nations based on the absolute magnitude of the numberprovided. In their study, respondents ignored the dis-tinction between relative frequencies (4.15 timesgreater) and relative percentages (415% greater), andfocused on the difference between the absolute magni-tude of the numbers (4.15 and 415).

The effect of different information formats can besalient in the domain of investment decisions, andthese differences may influence investor decisions. Inthis study, we manipulated the format we used to pro-vide individuals with investment returns. In this way,we were able to assess how different information for-mats led to different investing decisions. In particular,the experiments presented here focused on two wellknown dilemmas in investor behavior: the dispositioneffect and the status quo bias.

The Disposition Effect

The disposition effect refers to investors’ ten-dency to sell winning investments too early, andride losing investments too long (Shefrin andStatman [1985]). The disposition effect is diffuseamong individuals, but professional investors arealso affected by it, albeit at a lower rate. Odean[1998] analyzed a database with thousands of in-vestment trades and demonstrated that the disposi-tion effect is present all year, except during De-cember. In December there is a significant increasein the rate of losers traded, probably because inves-tors who end the year with some losses obtain atax benefit from realizing them.

The disposition effect is coherent with predictionsfrom prospect theory about how people perceivelosses. Prospect theory states that individuals are loss-(and risk-) averse when facing positive outcomes(gains), and risk-seeking when facing negative out-comes (losses) (Kahneman and Tversky [1979],Tversky and Kahneman [1981]). Thaler [1999] sug-gests investors feel selling a losing investment as a painbecause it obliges them to face an unrecoverable loss.As a result, investors prefer to hold the loser, just asthey prefer to accept a gamble instead of a sure loss,even if the gamble is characterized by the probabilityof losing more money than the sure loss.

The disposition effect is also coherent with theoriesabout decision regret (Bell [1982]). Winners are soldquickly because investors prefer to avoid the regret dueto a market trend change that can reduce their gains.More often, though, investors tend to sell winningstocks while their value is still rising.

The Status Quo Bias

The tendency to avoid losses and uncertainty is alsoresponsible for the status quo bias. Individuals influ-enced by the status quo bias tend to postpone their de-cisions or to maintain their current situation unchangedinstead of choosing an uncertain outcome (Kahneman,Knetsch, and Thaler [1991]). In the domain of finance,the status quo bias is seen in investors who hold onto alosing portfolio because they fear incurring evengreater losses.

Samuelson and Zeckhauser [1988] demonstratedexperimentally the existence of the status quo bias infinancial decision making. The authors told two groupsthat they had inherited a large amount of money, andasked how they preferred to invest it. In the first condi-tion, individuals inherited cash and were asked to de-cide between two investment portfolios. In the secondcondition, individuals inherited money already in-vested in one of the two portfolios, and had to decidewhether to switch their portfolio or not.

Results demonstrated a strong status quo bias in thesecond group. In the first condition, there were no dif-ferences between how many individuals chose the firstor the second portfolio; in the second condition, how-ever, the majority preferred to remain in their originalportfolio. The explanation is that individuals in the sec-ond condition preferred not to change because of thestrong regret they might feel in case of a loss.

Experiment 1

Experiment 1 assessed the impact of different infor-mation formats on investment decisions. People oftenlearn about investment trends from newspapers or TVdescribing the stock’s price day by day. For example, Ican learn that Microsoft stock is currently at $27.32.

Stock returns are often described as the differencebetween the buying price and the selling price. So if thebuying price is $0.98 and the selling price is $1.22, thestock value is said to have increased $0.24. But stockreturns are also described as percentages. So in thiscase we could also say the stock return is 24% (the sell-ing stock value is 24% greater than the buying value).Or, we could describe the return as a ratio between thebuying price and the selling price. In that case, thestock return would be about ¼ (the selling stock valueis ¼ greater than the selling value).

Even if all these formats are logically equivalent, itis plausible to expect that people will perceive themdifferently. For example, a $0.24 increase might beperceived as lower than a 24% increase, because peo-ple tend to focus on the absolute magnitude of the num-bers more than on their statistical meaning. In ourstudy, the stock returns of two funds were described in

20

RUBALTELLI ET AL.

Dow

nloa

ded

by [

Uni

vers

ity o

f B

ath]

at 0

3:20

04

Oct

ober

201

4

four different formats, as shown in Table 1. One fundwas said to be losing, the other to be gaining.

When people are told “the mean stock price of fundA has gained one-quarter of its starting value and themean stock price of fund B has lost one-fifth of itsstarting price,” they can easily understand that theamount gained in the first fund is equal to the amountlost in the second fund. If people realize their wealthhas not changed, even if it is differently distributed,they are more likely to keep both funds and await fu-ture market trends. This conservative behavior is indic-ative of the status quo bias (Kahneman, Knetsch, andThaler [1991]). Because ratios can be easily imagined,we could say that meaning is attached to ratios quiteeasily (unless they are extremely complicated, such as856/963). For example, 8/10 can easily be imagined aseight pieces over ten.

Our first hypothesis is therefore as follows:

Hypothesis 1: If returns are expressed as ratios,people are more prone to exhibit the status quobias.

But ratios are not the only way by which informa-tion can become meaningful. According to Halpern,Blackman, and Salzman [1989], people tend to focusprimarily on the absolute magnitude of numbers. Wetherefore expect that stating “there was an increase of24% in the mean price of stock fund A and a decreaseof 19% in the mean price of stock fund B” would ren-der these gains and losses more relevant to investorsthan when they are expressed in other formats. As aconsequence, investors might be more willing to real-ize the loss by selling the losing fund. This behavior ispredictable on the basis of the stop-loss effect: When aloss is too high, you sell. And when information is pre-sented as percentages, people should be less prone tothe status quo bias and the disposition effect.

Our second hypothesis is therefore as follows:

Hypothesis 2: When stock returns are describedas percentages, participants will sell a losingfund more frequently than when they are de-scribed in a different format.

Method

The participants in Experiment 1 consisted of 480undergraduate students: 35% male, 65% female, with amean age of twenty-two. Participants were assignedrandomly to one of four experimental conditions, soeach condition contained 120 students.

The material used is shown in the Appendix. Partic-ipants were asked to assume that twelve months agothey had invested in two stock funds, “fund A” and“fund B.” They were told that a different amount ofmoney was invested in the two funds ($1,583 in fund A

and $2,000 in fund B), and that the mean stock price, atthe time they decided to invest, was the same for bothfunds ($0.98 per stock). Finally, they were told that thetwo funds were invested in different assets.

The participants were then given the returns of thefunds after twelve months and told that one had gainedvalue while the other had lost. The amount of moneygained and lost in each fund was the same, but the rateof gain and loss was different because of the differentamount of money allocated to each fund. Participantswere not told the exact amount of money gained andlost but were given the two stock fund returns.

According to the experimental condition, each par-ticipant was presented with the same information aboutreturns in one of four different formats (see Table 1).To avoid possible order effects, half the participants ineach condition were told that stock fund A was gainingand stock fund B was losing, while the other half weretold the opposite. The participants’ task was to make achoice among four investment strategies: 1) sell thegaining fund and keep the losing fund; 2) sell the losingfund and keep the gaining fund; 3) keep both funds; or4) sell both funds. Participants were then asked to ratetheir confidence in the choice and to briefly note thereasons for their choice. We assessed confidence byasking participants to answer the question “how confi-dent are you that the new investment strategy is the bestamong those presented?” using a seven-point scale,ranging from 1 = not at all confident to 7 = completelyconfident.

Furthermore, we used confidence as a manipulationcheck. We reasoned that if the different formats gavethe participants the impression that the amount ofmoney lost and gained was different, then they shouldshow more confidence when the perceived amount wasgreater (as in the percentage condition).

Design and Procedure

The information format was a between-subjectsfactor with four levels (percentages, selling price, dif-

21

NUMERICAL INFORMATION FORMAT AND INVESTMENT DECISIONS

Table 1. Information Formats

InformationFormat Fund A Fund B

Percentages Stock fund Aexperienced a 24%increase in its meanprice.

Stock fund Bexperienced a 19%decrease in its meanprice.

Selling Price The mean stock price offund A is now $1.22.

The mean stock price offund B is now $0.74.

Difference The mean stock price offund A has increased by$0.24.

The mean stock price offund B has decreasedby $0.19.

Ratios The mean stock price offund A has gained 1/4of its starting value.

The mean stock price offund B has lost 1/5 ofits starting value.

Dow

nloa

ded

by [

Uni

vers

ity o

f B

ath]

at 0

3:20

04

Oct

ober

201

4

ference, and ratios). The investment strategy was thedependent variable, and the experiment was adminis-tered during class hours. Every participant read thescenario individually and held onto it until the end ofthe experiment, when they were asked to choose an in-vestment strategy. Participants were then asked theconfidence question and the reasons for their choice.The order of presentation of the two fund returns (gain-ing or losing) was counterbalanced across conditions.

Results

Investment strategy. We performed a 2 × 4[(fund returns order) × (investment strategy)] log-lin-ear analysis to test for an order effect of the two fundreturns (gaining or losing). No significant effect wasfound, χ2 (7, N = 480) = 0.000, n.s., and further analy-ses considered the combined data set.

Figure 1 shows the mean frequencies for each in-vestment strategy in the four conditions. A 4 × 4 [(typeof information format) × (investment strategy)]log-linear analysis showed a main effect of the invest-ment strategy, χ2 (3, N = 480) = 167.156; p. = 0.001,and a significant interaction between the type of infor-mation format and the investment strategy, χ2 (9, N =480) = 19.874; p. = 0.019. As Figure 1 shows, the twoalternatives “sell the gaining fund” and “keep bothfunds” seemed to be preferred over the others.

A descriptive analysis of the frequencies reveals theprevalence of the status quo bias, as shown by the high

percentage of people choosing to “keep both funds.” Tostatistically test whether the preferences for the biasedstrategy were higher than those for the theoreticallybest alternative, “sell the losing fund,” we performed a2 × 4 [(investment strategy: “keep both funds” versus“sell the losing fund”) × (type of information format)]log-linear analysis. Participants showed the status quobias across all conditions: The “keep both funds” alter-native was generally preferred over “sell the losingfund” (42% versus 14%), as illustrated by the signifi-cant main effect of investment strategy, χ2 (1, N = 269)= 75.422; p. = 0.0001.

The frequencies also show that the participantswere systematically affected by the disposition effect,in that they were less prone to sell the losing fundthan to sell the gaining one (35% versus 14%). Tostatistically test this evidence, we performed a 2 × 4[(investment strategy: “sell the gaining fund” versus“sell the losing fund”) × (type of information for-mat)] log-linear analysis. A significant main effect ofinvestment strategy was found, χ2 (1, N = 235) =48.616; p. = 0.0001.

Returning to our first hypothesis, we expected thatreturns expressed as ratios (rather than another for-mat) would induce more people to exhibit the statusquo bias. When the frequency of people choosing to“keep both funds” and to “sell the gaining fund” arecompared across conditions, the results show a signif-icant interaction effect of the 2 × 4 [(investment strat-egy: “keep both funds” versus “sell the losing fund”)× (type of information format)] log-linear analysis, χ2

22

RUBALTELLI ET AL.

FIGURE 1Frequency of Choices for the Four Alternatives in Each Condition of Experiment 1

Dow

nloa

ded

by [

Uni

vers

ity o

f B

ath]

at 0

3:20

04

Oct

ober

201

4

(3, N = 269) = 10.947; p. = 0.012. In the ratios condi-tion, 54% of the participants chose to “keep bothfunds,” while 11% chose to “sell the losing fund,”and this difference is the greatest across conditions.At the same time, due to the increase of the statusquo bias, the percentage of people showing a disposi-tion effect decreased.

Our second hypothesis predicted that when stockreturns are described as percentages (rather than an-other format), participants will sell the losing fundmore frequently. We tested whether the frequency ofpeople choosing to “sell the losing fund” changedacross the four conditions. A chi-squared analysis gavea significant interaction effect of χ2 (3.65) = 7.923; p =0.048. Participants preferred to sell the losing fundmore often in the percentage condition than in the otherconditions (22% versus 10%, 12%, and 11%). Further-more, the percentage condition is the only one in whichthe difference between the percentage of participantschoosing to sell the gaining fund and sell the losingfund is not statistically significant (21.7% versus32.5%), χ2 (1, 120) = 2.600; p. = 0.107. In this condi-tion, the disposition effect seems to be highly reduced.

Confidence. We analyzed participant confidenceratings in an analysis of variance with type of informa-tion format as the between-subjects factor. This analy-sis showed no difference in participant confidence rat-ings between the four information formats, F (3.477) =0.604, η2 = 0.004, n.s. The confidence ratings did notparallel the changes in frequency of people choosingthe different alternatives. This result suggests that in-formation format impacts investment strategies, butthat individuals do not recognize this influence.

Discussion. The two major findings of Experi-ment 1 are that:

1. Describing stock returns as ratios increases atendency toward the status quo bias.

2. Describing stock returns as percentages in-creases the likelihood that an individual willsell the losing fund (and decreases the influ-ence of the disposition effect).

The first result can be explained by assuming thatratios make the perception of gains and losses moresimilar, and induces people to think that no relevantchange in their global wealth has occurred. This wouldprobably increase the status quo bias.

The second result is attributable to the fact that peo-ple tend to focus on the absolute magnitude of a num-ber and not on its statistical value. The absolute magni-tude of the number would bring an implicit meaning of“high versus low,” which is processed automatically,independently from the statistical meaning. In the per-

centage condition, the absolute magnitude of thenumber is the highest, and, as predicted, it is the onlycondition where the disposition effect is reduced. Wedesigned Experiment 2 to further investigate the abso-lute magnitude effect.

Experiment 2

Experiment 2 explores the impact of the absolutemagnitude effect on investors’ perception of fund re-turns. We replicated two of the conditions previouslyused in Experiment 1, the “percentages” and the “dif-ference” conditions. In these conditions, the same in-formation is presented in different formats but withequivalent statistical meaning. The different formatsimply different absolute magnitudes. For percentages,the absolute magnitude is high (e.g., 24%), while forthe difference the absolute magnitude is low (e.g.,$0.24). According to the absolute magnitude effect, thedifferent magnitudes will produce different percep-tions of how much each fund has gained and lost.

We posited the following:

Hypothesis: People will be more satisfied withthe gaining fund and less satisfied with the losingfund when the absolute magnitude (percentagecondition) is high, versus when it is low (differ-ence condition). This occurs because when theabsolute magnitude is high, people perceive thatthe losing fund has lost more and the gainingfund has gained more.

Method

The participants in Experiment 2 consisted of 170undergraduate students: 36% male, 64% female, with amean age of twenty-one. Participants were assignedrandomly to the “percentage” (eighty-six students) orthe “difference” conditions (eighty-four).

Experiment 2 used the same material as Experi-ment 1, but we administered only the “percentage”and “difference” conditions. The participants’ taskagain was to read the scenario, and choose amongfour investment strategies: 1) sell the gaining fundand keep the losing fund; 2) sell the losing fund andkeep the gaining fund; 3) keep both funds; or 4) sellboth funds. The difference here is that participantswere asked to answer two questions after making thechoice: “How happy are you about the returns fromstock fund A?” and “how happy are you about the re-turns from stock fund B?” The answers were given onan eleven-point scale, from –5 for “not at all happy,”to +5 for “extremely happy.”

23

NUMERICAL INFORMATION FORMAT AND INVESTMENT DECISIONS

Dow

nloa

ded

by [

Uni

vers

ity o

f B

ath]

at 0

3:20

04

Oct

ober

201

4

Design and Procedure

We manipulated the “type of information format”(percentage versus difference), and recorded the in-vestment choice and each participant’s satisfactionwith funds A and B. The experiment was administeredduring class hours. Every participant read the scenarioindividually and again held it until the end of the exper-iment when they were asked to choose an investmentstrategy. The order of presentation of the two fund re-turns (the gaining and the losing funds) was counter-balanced across conditions.

Results

Figure 2 shows participants’ choices in the percent-age and difference conditions. The choices signifi-cantly parallel those of Experiment 1. In particular,more participants decided to sell the losing fund whengiven the percentage format (M = 67.5%) than whengiven the difference format (M = 32.5%), χ2 (1.68) =4.90; p = 0.027.

Consistent with these results, satisfaction with thelosing fund was lower in the percentage condition (M =-2.65; SD = 1.87) than in the difference condition (M =-2.06; SD = 1.75), t (170) = -2.13; p = 0.035. Further-more, satisfaction with the gaining fund was higher inthe percentage condition (M = 2.81; SD = 2.18) than inthe difference condition (M = 2.12; SD = 1.80), t (170)= 2.25; p = 0.026. As hypothesized, participants weremore satisfied with the gaining fund and less satisfiedwith the losing fund when the absolute magnitude washigh (percentage condition), versus when it was low(difference condition). Figure 3 displays participants’satisfaction with the two funds.

General Discussion

Investors have many choices when deciding how toinvest their money in the stock market. But all thechoices share a common feature: Daily returns go up ordown. To evaluate their decisions, investors routinelyassess these returns. From a rational point of view, itshould not matter whether they are expressed as a per-centage of variation between the buying value and theactual value (e.g., 24%), or as a monetary differencebetween the buying price and the actual price (e.g.,$0.24). However, studies repeatedly find that peopleare influenced by information formats.

In this study, we increased and decreased satisfac-tion with a fund and influenced people’s investingstrategies by manipulating only the numerical formatof the returns. This effect, called the “absolute magni-tude effect,” is the tendency to perceive numericalvalue according to absolute magnitude instead of sta-tistical meaning.

We showed how the different magnitude of the nu-merical information can produce different percep-tions of how much each fund has gained and lost. Asour experiments show, people perceived that the los-ing fund had lost more and the gaining fund hadgained more when the absolute magnitude was high(e.g., 24%) than when it was low (e.g., 0.24). Consis-tent with these perceptions, when the absolute magni-tude was high, people preferred to sell a losing invest-ment. When it was low, they preferred to sell againing investment or to maintain the status quo. Inthe specific context of this experiment, the percentageformat decreased the disposition effect significantly,which is the tendency to sell a gaining investment andhold a losing one.

24

RUBALTELLI ET AL.

FIGURE 2Frequency of Choices for the Four Alternatives in Each Condition of Experiment 2

Dow

nloa

ded

by [

Uni

vers

ity o

f B

ath]

at 0

3:20

04

Oct

ober

201

4

The absolute magnitude effect has widespread con-sequences in everyday life because it can impact anydecision that entails the presentation of numerical in-formation. For example, when consumers are pre-sented with a special sale offer, merchants could con-ceivably use percentages to imply that the price cut isgreater than it actually is. And being aware of the abso-lute magnitude effect is important for both advisorsand investors. Advisors can decide which way to pres-ent information to investors in order to give them theclearest picture of their investments; investors can helpprevent investment errors by ensuring they are notmisperceiving gains or losses.

This study, however, has two main limitations. First,we used a simplified scenario about investment deci-sions: Funds were anonymously defined as “A” and“B,” which allowed for no historical or affective mean-ing to be attached to them. Second, we tested a sampleof university students who had no investing expertise.Even if cognitive biases such as the disposition effector the status quo bias are common among experts, areal investor might overcome the absolute magnitudeeffect. Future research should be directed at investigat-ing the absolute magnitude effect in real-world con-texts with real investors.

References

Bell, D.E. “Regret in Decision Making under Uncertainty.” Opera-tions Research, 5, (1982), pp. 960–981.

Gigerenzer, G., and U. Hoffrage. “How to Improve Bayesian Rea-soning without Instruction: Frequency Formats.” PsychologicalReview, 102, (1995), pp. 684–704.

Gigerenzer, G., and U. Hoffrage.“Overcoming Difficulties inBayesian Reasoning: A Reply to Lewis and Keren (1999) and

Mellers and McGraw (1999).” Psychological-Review, 106,(1999), pp. 425–430.

Halpern, D.F., S. Blackman, and B. Salzman. “Using Statistical RiskInformation to Assess Oral Contraceptive Safety.” AppliedCognitive Psychology, 3, (1989), pp. 251–260.

Johnson, E.J., J.W. Payne, and J.R. Bettman. “Information Displaysand Preference Reversals.” Organizational Behavior and Hu-man Decision Processes, 42, (1988), pp. 1–21.

Kahneman, D.E., J. Knetsch, and R. Thaler. “Anomalies: The En-dowment Effect, Loss Aversion, and Status Quo Bias.” Journalof Economic Perspectives, 5, (1991), pp. 193–206.

Kahneman, D., and A. Tversky. “Prospect Theory: An Analysis ofDecision under Risk.” Econometria, 47, (1979), pp. 263–292.

Odean T. “Volume, Volatility and Profit when All Traders are AboveAverage.” Journal of Finance, 53, (1998), pp. 1887–1934.

Samuelson W., and R. Zeckhauser.“Status Quo Bias in DecisionMaking.” Journal of Risk and Uncertainty, 1, (1988), pp. 7–59.

Shefrin H., and M. Statman. “The Disposition to Sell Winners TooEarly and Ride Losers Too Long: Theory and Evidence.” Jour-nal of Finance, 40, (1985), pp. 777–790.

Stone, E.R., J.F. Yates, and A.M. Parker. “Risk Communication: Ab-solute versus Relative Expressions of Low Probability Risks.”Organizational Behaviors and Human Decision Processes, 60,(1994), pp. 387–408.

Thaler R.H. “Mental Accounting Matters.” Journal of BehavioralDecision Making, 12, (1999), pp. 183–206.

Tversky A., and D.E. Kahneman.“The Framing of Decisions and thePsychology of Choice.” Science, 211, (1981), pp. 453–458.

APPENDIXMaterials Used in Experiment 1

Scenario Common to all Conditions

Imagine you have decided to invest a certainamount of money in the stock market. You choose toinvest in stock funds A and B, $1,583 in fund A, and$2,000 in fund B. At the time you decide to invest, thetwo stock funds have the same mean stock value ($0.98

25

NUMERICAL INFORMATION FORMAT AND INVESTMENT DECISIONS

FIGURE 3Participants’ Judgments of Satisfaction With Fund A and Fund B

Dow

nloa

ded

by [

Uni

vers

ity o

f B

ath]

at 0

3:20

04

Oct

ober

201

4

per stock), but they are made up of stocks from differ-ent industrial sectors.

Percentage

After twelve months, you check the trend of your in-vestments, and note the following:

• The mean price of fund A has increased by 24%.• The mean price of fund B has decreased by 19%.

What investment strategy do you deem best for thefuture among the strategies that your financial advisorhas suggested?

Selling Price

After twelve months, you check the trend of your in-vestments, and note the following:

• The mean stock price of fund A is now $1.22.• The mean stock price of fund B is now $0.79.

What investment strategy do you deem best for thefuture among the strategies that your financial advisorhas suggested?

Difference

After twelve months, you check the trend of your in-vestments, and note the following:

• The mean stock price of fund A has increased by$0.24.

• The mean stock price of fund B has decreased by$0.19.

What investment strategy do you deem best for thefuture among the strategies that your financial advisorhas suggested?

Ratios

After twelve months, you check the trend of your in-vestments, and note the following:

• The mean stock price of fund A has gained 1/4 ofits starting value.

• The mean stock price of fund B has lost 1/5 of itsstarting value.

What investment strategy do you deem best for thefuture among the strategies that your financial advisorhas suggested?

26

RUBALTELLI ET AL.

Dow

nloa

ded

by [

Uni

vers

ity o

f B

ath]

at 0

3:20

04

Oct

ober

201

4