Behaviour Finance Flashcards
Behavioral Finance vs Traditional Finance
Behavioral Finance
- Descriptive (what investors do)
- Cognitive limits and Emotional biases
- Bounded rationality, loss averse and prospect Theory
- Market prices may not be efficient
Traditional Finance
- Normative (what investors should do)
- Rational, risk-averse and consistent with utility theory to max satisfaction
- Updated expectations (perfect info) and unbiased
- The price is right (i.e. Market is efficient)
- No free lunch (i.e. No alpha for port managers)
4 axioms of Utility Theory
If all holds, individual is rational
- Completeness: “choices and preferences” - well-defined preference and clearly decides b/w 2 choices (A > B)
- Transitivity: rankings are applied consistently (if A > B and B > C, then A > C)
- Independence: new item does not change independent utility of original items (if A > B then [A + C] > [B + C]) – utilities are additive and divisible
- Continuity: smooth and continuous (unbroken) indifference curve
Bayes’ Formula
Bayes Formula – With new information, investors revise expectations applying baysian analysis (i.e. conditional probability)
P (A | B) = [P (B | A) * P (A)] / P (B) = probability of A given B (eg. A urns, B red ball.)
Decision tree under Traditional Finance
- Adhere to the axioms of the utility function
- Assign probabilities and analyse using Bayes’ Formula (conditional probability)
- Chose the max. exp. utility subject to budget constrains
Rational Economic Man (REM)
- Perfectly rational
- Perfectly informational
- Prefectly selfish
Review all information and ajust all info thinking only about yourself
Risk premium
Expected return = risk premium + risk free
Risk Premium = E(r) - Certainty Equivalent (ie. rf)
Utility Function - Traditional Finance vs. Behaviour Finance
Traditional finance - Continous where individous are risk averse (concave, eg. insurance, low probability, avoiding risk), risk loving (convex, eg. lottery ticket, with low probability, but seeking risk) or risk neutral
Behaviour Finance - Double inflection utility function, where utility function may change based on the level of wealth (eg. risk seeking for gains and risk averse for losses)
Prospect Theory
Prospect Theory - Alternative to utility theory, dependent on framing effects
- Focus on perceived gains / losses (Δ wealth) based on a reference point
- Subjective decision weights replace objective probability
Behavior Finance Decision making in 2 phases:
(i) Editing phase - Organize and reformulate options to simplify the choice (subject to isolation effect, where investors focus on one factor and ignore others)
(ii)Evaluation phase - people are loss-averse and reference dependent (evaluate decisions based on its gain/loss, level of wealth or income) – decisions are made based on wpv (weight * probability * value), assigning discretionary weights depending on the possible outcome (gain / loss)
Bounded Rationality
Bounded Rationality
Relaxes perfect information and process according to expected utility theory.
People will satisfice (satisfy + suffice) when pursuing a specific goal while finding solutions that are bounded by constraints (such as time and money). It may not be optimal, but it is acceptable / adequate meeting the criteria specified.
When some (but not all) information is available, use heuristics (rule of thumb).
Forms of Efficient Market Hypothesis
(and market anomalies)
(i) Weak form: Prices reflect all past price and volume (i.e. technical analysis will not generate excess return)
(ii) Semi-strong form: Prices reflect all public information, including prices, volume and data (i.e. technical and fundamental analysis will not generate excess return)
(iiI) Strong form: Prices reflect all public and private information (i.e. technical, fundamental or insider information will not generate excess return)
Market anomalies: Fundamental (small vs large cap), Technical (moving avg) and Calendar (January effect)
Traditional Finance Portfolio Construction
Mean-variance efficient (rational portfolio), subject to investment constraints and objectives
Behavioral Finance Portfolio Construction
Consumption and Savings
People are subject = Self -control (people may focus on short term satisfaction) + Mental accounting (treat a sum of money different from another sum of money) + Framing bias (different response for different forms of asking the same question)
Behavioral Finance Portfolio Construction
Asset Pricing
CAPM + SDF = rf + risk premium + sentiment premium (i.e. stochastic discount factor considering dispersion of analysts forecast)
Behavioral Finance Portfolio Construction
Behavioral Portfolio Theory (BPT)
Behavioral Portfolio Theory (BPT) - Correlation between layers is not considered (sub-optimal from TF perspective, but is the portfolio that the client can live with)
(i) Portfolio built in layers according to goal (risk-return) and importance given to each
(ii) Goal in each layer determine how much it is allocated to it
(iii) # of assets depends on the shape of utility curve (the greater the concavity, the greater the # of securities)
(iv) Investors with perceived info advantage will hold more concentrated positions
(v) Investors that are highly loss averse may hold cash to avoid selling assets and realize losses
Behavioral Finance Portfolio Construction
Adaptive Markets Hypothesis (AMH)
Adaptative Markets Hypothesis (AMH) – Principles of evolution to financial markets. Bounded rationality and satisficing via trial and error
(i) Investors make decisions to help them survive (satisfice) rather than to maximize utility (optimal).
(ii) Investors must adapt and innovate to survive.
(iii) No investment strategy can continually out-perform.
(iv) Risk premiums vary over time with changes in (1) risk aversion and (2) the level of competition.
(v) Active management can add value by arbitrage opportunities
Behavioral Biases:
Cognitive errors vs Emotional biases
Cogntive errors:
- processing shortcuts or heuristics / memory errors, such as inability to do complex math calcs or processing and filtering information.
- Result of faulty reasoning.
- Better info, education, and advice can often correct it.
Emotional biases:
- Emotional or motivational factors, steamed by impulse or intuition.
- Reasoning influenced by feelings.
- Less easily corrected, recognize and adapt
Cognitive Errors
Belief Perseverance Biases
CC-RIH’der
Conservatism bias
Confirmation bias
Representativeness bias
Illusion of control bias
Hindsight bias
Cognitive Errors
Information-Processing Biases
FAMA
- Anchoring & Adjustment
- Mental accounting bias
- Framing bias
- Availability bias
Emotional Biases
LOSERS
-
Loss aversion bias
(i) Myopic loss aversion -
Overconfidence bias (illusion of knowledge)
(i) Prediction overconfidence
(ii) Certainty overconfidence
(iii) Self-Attribution bias -
Self-control bias
(i) Hyperbolic discounting - Endowment bias
- Regret-aversion bias
- Status quo bias