Can Investing Diaries be Hazardous to Your Financial Health?
Keywords:Prediction markets, confirmation bias, hindsight bias, explanation effect, market efficiency, behavioral finance
AbstractBusiness writers and academics have suggested keeping an investing diary to avoid hindsight bias. In the diary, investors justify their predictions of future events, e.g., “This stock will go up because…” Eliminating hindsight bias should improve future returns. However, psychological research on the “explanation effect” suggests that justifying one’s predictions in writing induces overconfidence and, by consequence, reduces current returns. We test these propositions in a set of prediction markets populated by two types of traders: forecasters who completed a required investing diary task and non-forecasters who did not. The portfolios of forecasters were significantly over-invested in securities associated with the forecaster’s prediction. This is consistent with prior psychological research and a clear sign of investor over-confidence. We further find that forecasters with accurate predictions have higher returns than those with inaccurate predictions. However, the returns for forecasters with inaccurate predictions were generally no worse than the returns of the non-forecasters. Our results suggest that while keeping an investing diary may lead to biased portfolios, it does not have an overall negative effect on current returns. Therefore, contrary to expectations, there is not a trade-off between the long-term and short-term effects of an investing diary.
CA Anderson, MR Lepper, and L Ross ‘The perseverance of social theories: The role of explanation in the persistence of discredited information’ (1980) 39 Journal of Personality and Social Psychology, pp. 1037-1049.
HR Arkes ‘The Consequences of the Hindsight Bias in Medical Decision Making’ (2013) 22 Current Directions in Psychological Science 5, pp. 356-360.
BM Barber and T Odean ‘Online Investors: Do the Slow Die First?’ (2002) 15 The Review of Financial Studies 2, pp. 455–488.
N Barberis and R Thaler ‘A survey of behavioral finance’ in GM Constantinides, M Harris and R Stulz (eds) Handbook of the Economics of Finance (Elsevier Science, 2001).
G Belsky and T Gilovich Why Smart People Make Big Money Mistakes And How To Correct Them: Lessons From The New Science Of Behavioral Economics (New York, Simon and Schuster, 2000).
JE Berg, FD Nelson and T Rietz ‘Prediction Market Accuracy in the Long Run’ (2008) 24
International Journal of Forecasting 2, pp. 283-298.
B Biais and M Weber ‘Hindsight Bias, Risk Perception and Investment Performance’ (2009) 55 Management Science 6, pp. 1018-1029.
H Blank, V Fischer and E Erdfelder ‘Hindsight bias in political elections’ (2003) 11 Memory 4-5, pp. 491-504
G Bodenhausen ‘Stereotypic biases in social decision making and memory: testing process models of stereotype use’ (1988) 55 Journal of Personality and Social Psychology, pp. 726-737.
O Bondarenko and P Bossaerts ‘Expectations and learning in Iowa’ (2000) 24 Journal of Banking & Finance 9, pp. 1535-1555.
B Carey ‘That Guy Won? Why We Knew It All Along’ (October 29, 2012) New York Times. See https://www.nytimes.com/2012/10/30/health/he-won-the-election-i-knew-it-all-along.html?pagewanted=all.
JJ Christensen-Szalanski and C Fobian-Willham ‘The hindsight bias: A meta-analysis’ (1991) 48 Organizational Behavior and Human Decision Processes 1, pp. 147-168.
S Constable ‘How to Keep an Investment Diary’ (May 17, 2016) US News and World Report. See https://money.usnews.com/investing/articles/2016-05-17/how-to-keep-an-investment-diary.
K Daniel, D Hirshleifer and A Subrahmanyam ‘Investor Psychology and Security Market Under- and Overreactions’ (1998) 53 Journal of Finance 6, pp. 1839-1886.
MF Davies ‘Reduction of hindsight bias by restoration of foresight perspective: Effectiveness of foresight-encoding and hindsight-retrieval strategies’ (1987) 40 Organizational Behavior and Human Decision Processes 1, pp. 50–68.
PH Ditto, GD Munro, A Apanovitch, JA Scepansky and LK Lockhart ‘Motivated sensitivity to preference-inconsistent information’ (1998) 75 Journal of Personality and Social Psychology 1, pp. 53-69.
MJ Eames, SM Glover and JJ Kennedy ’Stock Recommendations as a Source of Bias in Earnings Forecasts’ (2006) 18 Behavioral Research in Accounting, pp. 37-51.
K Elkins ‘A brief history of the 401(k), which changed how Americans retire’ (January 4 2017) CNBC.com. See https://www.cnbc.com/2017/01/04/a-brief-history-of-the-401k-which-changed-how-americans-retire.html.
E Erdfelder and A Buchner ‘Decomposing the hindsight bias: A multinomial processing tree model for separating recollection and reconstruction in hindsight’ (1998) 24 Journal of Experimental Psychology: Learning, Memory, and Cognition 2, pp. 387–414
B Fischhoff ‘Perceived informativeness of facts’ (1977) 3 Journal of Experimental Psychology: Human Perception and Performance, pp. 349–358.
R Forsythe, F Nelson, GR Neumann and J Wright ‘Anatomy of an Experimental Political Stock Market’ (1992) 82 American Economic Review, pp. 1142-1161.
R Forsythe, M Frank, V Krishnamurthy and TW Ross ‘Markets as Predictors of Election Outcomes: Campaign Events and Judgement Bias in the 1993 UBC Election Stock Market’ (1998) 24 Canadian Public Policy 3, pp. 329-351.
S Gervais and T Odean ‘Learning to Be Overconfident’ (2001) 14 The Review of Financial Studies 1, pp. 1–27.
S Goins, TS Gruca and MC Cipriano ‘Private Information, Overconfidence and Trader Returns in Prediction Markets’ (2015) 9 Journal of Prediction Markets 3, pp. 1-21.
PA Granhag., LA Strömwall and CM Allwood ‘Effects of Reiteration, Hindsight Bias, and Memory on Realism in Eyewitness Confidence’ (2000) 14 Applied Cognitive Psychology 14, pp. 397-420.
SJ Grossman and JE Stiglitz ‘On the impossibility of informationally efficient markets’ (1980) 70 The American Economic Review 3, pp. 393-408.
TS Gruca ‘The IEM movie box office market: Integrating marketing and finance using electronic markets’ (2000) 22 Journal of Marketing Education 1, pp. 5-14.
J Hales ‘Directional Preferences, Information Processing and Investors’ Forecasts of Earnings’ (2007) 45 Journal of Accounting Research 3, pp. 607-628.
JS Hammersley, K Kadous and AM Magro ‘Cognitive and Strategic Components of the Explanation Effect’ (1997) 70 Organizational Behavior and Human Decision Processes 2, pp. 149-158.
J Han and H Tan ‘Investors’ reactions to Management Earnings Guidance: The Joint Effect of Investment Position, News Valence and Guidance Form’ (2010) 48 Journal of Accounting Research 1, pp. 81-103.
SS Hawkins and R Hastie ‘Hindsight: Biased judgments of past events after the outcomes are known’ (1990) 107 Psychological Bulletin 3, pp. 311–327.
T Hens and A Meier Behavioral finance: the psychology of investing (Switzerland, Credit Suisse, 2015).
G Hoffman ‘Investing in shares: a guide for beginners’ (June 10, 2015) Money Magazine, See https://www.moneymag.com.au/investing-in-shares-for-beginners.
J Huber ’J-shaped returns to timing advantage in access to information – Experimental evidence and a tentative explanation’ (2007) 31 Journal of Economic Dynamics and Control, pp. 2536-2572.
J Huber. M Angerer and M Kirchler ‘Experimental asset markets with endogenous choice of costly asymmetric information’ (2011) 14 Experimental Economics 2, pp. 223-240.
J Huber, M Kirchler and M Sutter ‘Is more information always better? Experimental financial markets with cumulative information’ (2008) 65 Journal of Economic Behavior and Organization, pp. 86-104.
TB Hugh and GD Tracy ‘Hindsight bias in medicolegal expert reports’ (2002) 176 Medical Journal of Australia, pp. 277-278.
M Kirchler ‘Partial knowledge is a dangerous thing – On the value of asymmetric fundamental information in asset markets’ (2010) 31 Journal of Economic Psychology 4, pp. 643-658.
RE Krider and CB Weinberg ‘Competitive dynamics and the introduction of new products: The motion picture timing game’ (1998) 35 Journal of Marketing Research, pp. 1–15.
P Lim, S Stanley and MH Cheong. Value Investing in Asia: The Definitive Guide to Investing in Asia. (New York, John Wiley & Sons, 2017).
CG Lord, MR Lepper and L Ross ‘Biased assimilation and attitude polarization: The effects of prior theories on subsequently considered evidence’ (1979) 37 Journal of Personality and Social Psychology, pp. 2098-2110.
J Montie The little book of behavioral investing: how not to be your own worst enemy (New York, John Wiley & Sons, 2010).
DA Moore and PJ Healy ‘The trouble with overconfidence.’ (2008) 115 Psychological Review 2, pp. 502–517.
RS Nickerson ‘Confirmation bias: a ubiquitous phenomenon in many guises’ (1998) 2 Review of General Psychology, pp. 175-220.
T Odean ‘Volume, volatility, price, and profits when all traders are above average’ (1998) 53
Journal of Finance, pp. 1887-1934.
DM Pennock, S Lawrence, CL Giles and FA Nielsen ‘The power of play:
Efficiency and forecast accuracy in web market games’ (2002) In NEC Research Institute.
S Pouget, J Sauvagnat and S Villeneuve ‘A Mind is a Terrible Thing to Change: Confirmatory Bias in Financial Markets’ (2014) Toulouse School of Economics Working Paper.
RF Pohl and W Hell ‘No reduction in hindsight bias after complete information and repeated testing’ (1996) 67 Organizational Behavior and Human Decision Processes 1, pp. 49–58.
M Rabin and J Schrag ‘First impressions matter: a model of confirmatory bias’ (1999) 114
Quarterly Journal of Economics, pp. 37-82.
NJ Roese and KD Vohs ‘Hindsight Bias’ (2012) 7 Perspectives of Psychological Science 5. Pp. 411-426.
MR Lepper, F Strack and J Steinmetz ‘Social explanation and social expectation: Effects of real and hypothetical explanations on subjective likelihood’ (1977) 35 Journal of Personality and Social Psychology 11, pp. 817-829.
M Ross. and F Sicoly ‘Egocentric biases in availability and attribution’ In D Kahneman, P Slovic, and A Tversky (Eds.), Judgment under uncertainty: Heuristics and biases. (New York, Oxford University Press, 1982), pp. 129-152.
K Schredelseker ‘Anlagestrategie und Informationsnutzen am Aktienmarkt’ (1984) 36 Zeitschrift fur Betriebswirtschaftliche Forschung, pp. 44– 59.
SJ Sherman ‘On the Self-Erasing Nature of Errors of Prediction’ (1980) 39 Journal of Personality and Social Psychology, pp. 211-221.
SJ Sherman, RB Skov, EE Hervitz and CB Stock ’The effects of explaining hypothetical future events: From possibility to probability to actuality and beyond’ (1981) 17 Journal of Experimental Social Psychology, pp. 142-158.
SJ Sherman, KS Zehner, J Johnson and ER Hirt ‘Social explanation: The role of timing, set and recall on subjective likelihood estimates’ (1983) 44 Journal of Personality and Social Psychology, pp. 1127-1143.
RH Thaler. Misbehaving: The making of behavioral economics (New York, W W Norton & Co., 2015).
J Thayer ‘Determinants of Investors’ Information Acquisition: Credibility and Confirmation’ (2011) 86 The Accounting Review 1, pp. 1-22.
WF van Raaij ‘Consumer Financial Behavior’ (2014) 7 Foundations and Trends in Marketing 4, pp 231-351.
J Wolfers and E Zitzewitz ‘Prediction Markets’ (2004) National Bureau of Economic Research (NBER) See http://www.nber.org/papers/w10504.
G Wood ‘The knew-it-all-along effect’ (1978) 4 Journal of Experimental Psychology: Human Perception and Performance, pp. 345-353.
J Zweig Your Money and Your Brain: How the New Science of Neuroeconomics Can Help Make You Rich (New York, Simon and Schuster, 2007).