Behavioral Finance in Asset Management a Primer
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FEATURE Behavioral Finance in Asset Management A Primer By Marcus Schulmerich, PhD, CFA®, FRM Heuristic Simplification Biases inancial crises are taking place called behavioral biases. They played more frequently and their impact a central role in the development of Heuristics are experience-based tech- F is spreading across the globe— behavioral finance. niques that help us make decisions the latest examples are the 2007–2009 Slovic saw the relevance of behav- (Kahneman et al. 1982, 3–4). Three key Great Recession and stock market ioral concepts in finance and set out heuristics discussed in this article are crash. The need to better understand his thesis in two articles at the end of representativeness, anchoring/salience, and address the root causes of such the 1960s (Shefrin 2002, 7–8). Then, and loss aversion/prospect theory. crashes becomes ever more important. in 1974, Tversky and Kahneman intro- Loss aversion forms part of Kahneman Standard finance theory cannot duced the fundamental concept of heu- and Tversky’s prospect theory (1979, explain the phenomenon, but behav- ristics—the study of how people make 263–291, reviewed later in this article. ioral finance theory offers some com- decisions, rush to judgment, or solve In 2002, Kahneman and Smith were pelling explanations. Behavioral finance problems, often using their experiences awarded the Nobel Memorial Prize in supplements standard finance theory and biases. Since then, academics and Economic Sciences for their work in the by introducing behavioral and psycho- practitioners have incorporated heu- field of behavioral finance. logical criteria to help clarify investors’ ristics into behavioral finance and led Representativeness decision-making process. This article a vast research effort focusing on the outlines the background and key find- cause and effect of psychological biases Representativeness bias describes the ings of behavioral finance and examines in financial markets. tendency to evaluate a situation by the influence of behavioral biases in More recently, in 2001, David comparing it to generalities or stereo- stock market crashes. Hirshleifer5 published a concise over- types. It can be thought of as a mental view of the most important behavioral shortcut that helps decision makers An Introduction to Behavioral biases, as shown in table 1. The biases avoid the need to analyze similar pro- Finance are grouped into four categories: cesses again and again. In 1956, economist Vernon L. Smith1 • Self-deception (limits to learning) In investment decision-making, rep- was the first to introduce the concept • Heuristic Simplification resentativeness bias can arise either from of behavioral finance. At the time, the • Emotion/Affect base-rate neglect or sample-size neglect. investment community did not believe • Social Base-rate neglect: Investors attempt in the idea that human behavior influ- to determine the potential success of ences security prices. However, others Key biases are highlighted in table 1. an investment in a stock by contextual- such as the psychologists Paul Slovic,2 As examined below, these biases, in izing it in a familiar, easy-to-understand Amos Tversky,3 and Daniel Kahneman,4 large part, help explain the occurrence classification scheme. For example, an continued to analyze investors’ so- of stock market bubbles and crashes. investor might categorize a stock as a TABLE 1: OVERVIEW OF BEHAVIORAL BIASES BY HIRSHLEIFER Behavioral Biases Heuristic Simplification Self-Deception (limits to learning) Emotion/Affect Social Representativeness Overoptimism Ambiguity Aversion Herding Anchoring/Salience Overconfidence Self-Control (hyperbolic discounting) Contagion Loss Aversion/Prospect Theory Confirmation Mood Imitation Framing Self-Attribution Regret Theory Cascades Availability Hindsight Cue Competition Cognitive Dissonance Categorization Conservation Source: Hirschleifer (2001, 1,533–1,597) 42 Investments&Wealth MONITOR © 2013 Investment Management Consultants Association. Reprint with permission only. FEATURE TABLE 2: TYPES OF REPRESENTATIVENESS BIASES Type of Representativeness Bias Examples 1. Investors can make significant financial errors when they examine a money manager’s track record. They look at that past few quarters or years and conclude, based on inadequate statistical data, that a fund’s performance is the result of skilled allocation and security selection. Base-rate neglect 2. Investors also make similar mistakes when investigating track records of stock analysts. For exam- ple, they look at the success of an analyst’s past few recommendations, erroneously assessing the analyst’s aptitude based on this limited data sample. Investors often fail to judge the likelihood of an investment outcome because they choose an inap- Sample-size neglect propriate sample size of data on which to base their judgments. They incorrectly assume that small sizes are representative of real data: Researchers call this phenomenon the “law of small numbers.” Source: Pompian (2006, 66–67) “value stock” and draw quick conclusions or irrelevant experience. Shiller (2005, tive assessment—their views can be sig- about the risks and rewards that follow 148) defines two types of anchors: quan- nificantly influenced by suggestions, e.g., from that categorization. This reason- titative and moral. how the numbers are presented. In this ing ignores variables that can impact Quantitative anchors are numbers example, the answers are strongly influ- the success of the investment. Investors or quantitative variables used to make enced by the first numbers that appear in often embark on this erroneous path estimations. One obvious example is the question. because they perceive it as an easy alter- past stock prices. When faced with investment decisions, native to the diligent and more compli- Moral anchors play an important investors seem to get anchored in past cated research that’s actually required role when people compare the intuitive price changes and the average prices of when evaluating an investment. force of stories and reasons to hold their assets (Shefrin 2005, 51). Figure 1 shows Sample-size neglect: Investors fail investments against their perceived that financial analysts also fall victim to to accurately consider the sample size of need to consume the wealth that the quantitative anchoring: Their forecasts the data on which they are basing their investments represent. of the S&P 500 index from June 1991 judgments and incorrectly assume that While heuristics can aid in decision to June 2004 were highly correlated to small sample sizes are representative making, they sometimes lead to severe the past prices of the index (Montier of populations. When people do not and systematic investment errors 2005, 11). initially comprehend a phenomenon because they rely on intuitive judgments In discussing moral anchors, Shiller reflected in a series of data, they quickly that are categorically different from the (2005, 151–152) recalls The Millionaire link assumptions based on only a few rational models on which investment Next Door, which was a best seller of the available data points. Individuals decisions should be based. during the stock market boom of the prone to sample-size neglect are quick Consider the following example 1990s (Stanley and Danko 1996). The to treat properties reflected in such from Montier (2007, 25): In performing book explained that most millionaires small samples as properties that accu- calculations, the way equations are in the United States are not exceptional rately describe universal pools of data. presented appears to have a significant income earners but merely frugal savers— However, the small sample examined influence on the result. people who are not interested in buy- may not be representative of the real Two versions of the same calculation ing a new car every year, for instance. data. This is also known as the “law of are shown below. The book’s enticing story about invest- small numbers.” ment millionaires, who save rather than (a) 1 × 2 × 3 × 4 × 5 × 6 × 7 × 8 As illustrated by the examples in spend their money, was just the kind (b) 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 table 2, both types of representativeness of moral anchor needed to help sustain bias can lead to significant investment In both cases the answer is 40,320. the unusual bull market during the mid mistakes. However, experiments have shown that to late 1990s. using different ways of presenting this Reasons to hold stocks or other Anchoring/Salience question of calculating the factorial of investments also can take on ethical as Anchoring is the tendency of decision eight produces different results: well as practical dimensions. Our culture makers to use “anchor” values or beliefs In (a) the median answer was 512. may supply reasons to hold stocks and as the basis for an assessment. When In (b) the median answer was 2,250. other savings vehicles that are related asked to form an assessment, they estab- This test shows that when people are to our sense of identity as responsible, lish a judgment based on inappropriate asked to make a decision—say a quantita- good, or level-headed people. November/December 2013 43 © 2013 Investment Management Consultants Association. Reprint with permission only. FEATURE Loss Aversion/Prospect Theory FIGURE 1: S&P 500 INDEX LEVEL COMPARED TO S&P 500 INDEX LEVEL Loss aversion is the third type of heu- FORECASTS ristic bias with significant implications 1600 for the financial markets. Kahneman and Tversky (1979) introduced prospect