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PROSPECT THEORY
shikta Singh
Overview
This video introduces Prospect Theory, a psychological model developed by Kahneman and Tversky that explains how individuals make decisions under conditions of risk and uncertainty. Unlike traditional economic theories that assume rational agents, Prospect Theory posits that people evaluate potential outcomes based on perceived gains and losses relative to a reference point, exhibiting loss aversion and overweighting small probabilities. The video details the two phases of decision-making in Prospect Theory—editing and evaluation—and illustrates these concepts with examples like the framing effect and the disposition effect. It also discusses practical applications in financial advising, offering propositions for how advisors can manage client behavioral biases during asset allocation.
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Chapters
- Prospect Theory is a psychological model describing how people make decisions involving risk and uncertainty.
- It was developed by Daniel Kahneman and Amos Tversky in 1979 and is a cornerstone of behavioral economics and finance.
- The theory states that decisions are based on perceived gains or losses relative to a reference point, not absolute outcomes.
- It challenges the Expected Utility Theory by describing actual human behavior rather than idealized rational choices.
Understanding Prospect Theory is crucial because it explains why individuals often make decisions that deviate from pure rationality, impacting financial markets and personal financial planning.
The pain of losing $1,000 is perceived as greater than the pleasure of gaining $1,000, illustrating the asymmetrical evaluation of losses and gains.
- A central tenet is loss aversion: people feel the impact of a loss more strongly than an equivalent gain.
- Decisions are made relative to a subjective reference point, which varies based on individual circumstances.
- This leads to decisions being made in relative, not absolute, terms, contrasting with rational models.
- The theory incorporates diminishing marginal utility for both gains (concave function) and losses (convex function).
These concepts explain predictable patterns in human decision-making, such as why people are more sensitive to potential losses than to potential gains of the same magnitude.
When faced with a choice between a guaranteed $450 gain and a 50% chance of gaining $1,000, risk-averse individuals often choose the certain $450, even though the expected value of the gamble is higher.
- Prospect Theory suggests people overweight low-probability events and underweight high-probability events.
- Decision-making occurs in two phases: an editing phase and an evaluation phase.
- The editing phase involves framing choices and setting reference points.
- The evaluation phase uses a value function and a weighting function to assess prospects and make a decision.
Understanding these phases helps in recognizing how the presentation of information (framing) and the subjective weighting of probabilities influence choices, often leading to irrational outcomes.
Cancer patients are more likely to choose a treatment presented with a '90% survival rate' than one with a '10% mortality rate,' even though they describe the same outcome.
- Certainty Effect: People prefer guaranteed outcomes over gambles with higher expected utility.
- Small Probability Effect: People tend to overemphasize very small probabilities, leading to risk-seeking behavior in certain situations.
- Relative Positioning: Individuals focus more on relative gains/losses compared to others rather than absolute wealth changes.
- Loss Aversion: The strong tendency to avoid losses, even at the cost of foregoing potential gains.
These features highlight common psychological tendencies that influence investment decisions, such as the disposition effect (selling winners too early, holding losers too long).
An investor might hold onto a losing stock hoping it will recover to break-even, rather than selling it and realizing the loss, demonstrating loss aversion and the disposition effect.
- Financial advisors often struggle with clients who demand short-term reactions to market movements, deviating from long-term plans.
- The best asset allocation for a client may prioritize adherence to their psychological preferences over maximizing expected returns.
- Advisors must decide whether to moderate or adapt to a client's behavioral biases.
- Proposition 1 suggests adapting to biases for wealthier clients and moderating for less wealthy clients, based on the risk to their standard of living.
This section provides practical strategies for financial professionals to navigate client behavior, ensuring that investment advice aligns with both financial goals and psychological realities.
For a wealthy client prone to loss aversion, an advisor might adapt by recommending a slightly more conservative portfolio than optimal, to ensure the client feels comfortable and sticks to the plan.
- Proposition 2 suggests moderating cognitive biases (correctable with information) and adapting to emotional biases (driven by impulse).
- Cognitive biases stem from faulty reasoning and can often be corrected with better information or advice.
- Emotional biases arise from feelings and intuition, making them harder to correct.
- A blended approach may be necessary, combining moderation and adaptation based on the client's wealth and bias type.
Differentiating between cognitive and emotional biases allows for more tailored and effective interventions by financial advisors, leading to better client outcomes.
A client with overconfidence (cognitive bias) might be moderated by presenting data and historical performance, while a client with regret aversion (emotional bias) might be adapted to by structuring the portfolio to minimize potential future regret.
- Understanding and acknowledging biases is the first step to mitigating their effects.
- Strategies include focusing on the bigger picture, relying on quantitative criteria, diversifying portfolios, and controlling the investment environment.
- Regularly reviewing biases and rebalancing portfolios can help manage their impact.
- While biases cannot be entirely eliminated, their effects can be significantly reduced through awareness and structured approaches.
Implementing these guidelines empowers individuals and professionals to make more rational financial decisions, leading to improved long-term investment success.
An investor might use an 'emotional tracker' to monitor their feelings about market fluctuations and consciously decide whether to act on those emotions or stick to a pre-defined quantitative investment plan.
Key takeaways
- People's decisions under risk are not always rational; they are heavily influenced by how potential outcomes are framed as gains or losses.
- Loss aversion is a powerful psychological force, making the pain of losing significantly greater than the pleasure of an equivalent gain.
- The way probabilities are perceived is distorted; low probabilities are often overweighted, and high probabilities are underweighted.
- Framing effects demonstrate that the presentation of choices, not just the choices themselves, can alter decision-making.
- In financial advising, it's often more effective to align investment strategies with a client's psychological tendencies than to solely pursue maximum returns.
- Understanding the difference between cognitive and emotional biases is key to effectively managing them in financial planning.
- While behavioral biases are inherent, proactive strategies can significantly mitigate their negative impact on investment decisions.
Key terms
Prospect TheoryBehavioral FinanceBehavioral EconomicsLoss AversionReference PointExpected Utility TheoryFraming EffectEditing PhaseEvaluation PhaseValue FunctionWeighting FunctionDisposition EffectCertainty EffectCognitive BiasEmotional Bias
Test your understanding
- How does Prospect Theory explain why people might take greater risks to avoid a loss than to achieve a gain?
- What is the role of a 'reference point' in Prospect Theory, and how does it influence decision-making?
- Explain the concept of 'loss aversion' and provide an example of how it might manifest in investment behavior.
- How do the 'editing' and 'evaluation' phases of Prospect Theory differ, and what is the significance of the framing effect within these phases?
- What are the key differences between cognitive and emotional biases, and how might a financial advisor approach each differently?