econ

Validity and Bias in Probability Estimations

  • Projection Bias: The assumption that people will project their current preferences or beliefs into the future.

  • Remaining Effects: Other biases discussed include:

    • Mood Heuristic Pattern Bias
    • Magical Beliefs

  • Homework Assignments: The publication of the makeup assignment is planned for the break, but it will not be due until the Thursday after returning.

    • Homework is due tomorrow night.
    • Students facing transportation constraints should communicate flexibly regarding deadlines.
    • Assignments will be returned based on quiz participation, organized alphabetically.

Bayesian Probability Projection

  • Bayesian Probability Estimations: A statistical method that combines prior probabilities and new information to update beliefs about the likelihood of outcomes.
    • People tend to overestimate or underestimate probabilities based on various factors.
    • Reliance on heuristics and biases makes accurate probability estimations challenging due to cognitive shortcuts.

Law of Small Numbers

  • Definition: The law of small numbers refers to drawing broad conclusions about a larger population based on a small sample of data.

    • Example: Assuming that an outcome observed in a class represents a general trend across all students.
    • Larger, statistically random samples are needed for accurate conclusions.

  • Application of the Law:

    • Small sample sizes may yield extreme or fluke outcomes.
    • Lack of statistical randomness among participants (e.g., demographic homogeneity in a class).

Hot Hand Effect

  • Explanation: The phenomenon where individuals believe that a player who is on a scoring streak (in sports, for example) will continue to score successfully.

    • Originated in basketball, where players who make consecutive free throws are perceived to be in a 'zone' or have a 'hot hand'.

  • Mathematical Considerations:

    • The hot hand effect is debated; large sample sizes may show that previous successes do not guarantee continued success.
    • Recent studies may contradict the traditional view that a hot hand reliably leads to future success.

Gambler's Fallacy

  • Definition: The fallacy that future probabilities are altered by past events in independent random events.

    • For instance, belief that after several red outcomes on a roulette wheel, black is 'due' to occur, despite the independence of each spin.

  • Hot Hand vs. Gambler's Fallacy:

    • Hot hand suggests that skill leads to sustained success in trials.
    • Gambler's fallacy reflects a belief in balancing outcomes over time, which applies to random events.

Confidence and Self-Assessment Biases

  • Overconfidence: When individuals believe they are more skilled or knowledgeable than they actually are.

    • Common example includes students overestimating their performance on exams.
    • People often assume they perform better than the average.

  • Self-Evaluation Bias: The tendency to misjudge one’s own abilities and performance.

    • Often intertwined with being too confident or underconfident.

  • Self-Serving Bias: Attributing personal successes to one's own skill and failures to external factors.

    • Example includes sports fans attributing their team's loss to poor officiating rather than team performance.

  • Self-Attribution Bias: Ignoring information that contradicts one’s pre-existing beliefs or self-image.

Projection Bias and Changing Preferences

  • Concept: Assuming future preferences will remain the same as current ones.

    • Common in significant life choices, such as majors or investments.
    • Buying decisions made today may rely on the belief that tastes will not change over time.

  • Discussion Prompt: Identify examples where one's initial enthusiasm for an item or choice diminished over time without the influence of habituation.

    • Personal anecdotes shared in class about changing majors or tastes in hobbies.