The gain-loss asymmetry and single-self preferences

Kahneman and Tversky asserted a fundamental asymmetry between gains and losses, namely a “reflection effect” which occurs when an individual prefers a sure gain of $pz to an uncertain gain of$ z with probability p, while preferring an uncertain loss of $z with probability p to a certain loss of$ pz. We focus on this class of choices (actuarially fair), and explore the extent to which the reflection effect, understood as occurring at a range of wealth levels, is compatible with single-self preferences. We decompose the reflection effect into two components, a “probability switch” effect, which is compatible with single-self preferences, and a “translation effect,” which is not. To argue the first point, we analyze two classes of single-self, nonexpected utility preferences, which we label “homothetic” and “weakly homothetic.” In both cases, we characterize the switch effect as well as the dependence of risk attitudes on wealth. We also discuss two types of utility functions of a form reminiscent of expected utility but with distorted probabilities. Type I always distorts the probability of the worst outcome downwards, yielding attraction to small risks for all probabilities. Type II distorts low probabilities upwards, and high probabilities downwards, implying risk aversion when the probability of the worst outcome is low. By combining homothetic or weak homothetic preferences with Type I or Type II distortion functions, we present four explicit examples: All four display a switch effect and, hence, a form of reflection effect consistent a single self preferences.Reflection, gains, losses, experiments, risk attitude, Leex

Risk aversion and embedding bias

In Selten (1967) “Strategy Method,” the second mover in the game submits a complete strategy. This basic idea has been exported to nonstrategic experiments, where a participant reports a complete list of contingent decisions, one for each situation or state in a given sequence, out of which one and only one state, randomly selected, will be implemented. In general, the method raises the following concern. If S0 and S1 are two different sequences of states, and state s is in both S0 and S1, would the participant make the same decision in state s when confronted with S0 as when confronted with S1? If not, the experimental results are suspect of suffering from an “embedding bias.” We check for embedding biases in elicitation methods of Charles Holt and Susan Laury (Laury and Holt, 2000, and Holt and Laury, 2002), and of the present authors (Bosch-Domènech and Silvestre, 1999, 2002, 2006a, b) by appropriately chosen replications of the original experiments. We find no evidence of embedding bias in our work. But in Holt and Laury’s method participants tend to switch earlier to the riskier option when later pairs of lotteries are eliminated from the sequence, suggesting the presence of some embedding bias.Embedding bias, strategy method, Holt, Laury, Risk Attraction, Risk Aversion, Experiments, Leex

Does risk aversion or attraction depend on income? An experiment

Does risk attitude (aversion or attraction) vary with the level of the income at risk? About half of our subjects chose to insure all levels, whereas another half chose instead not to insure low levels, but to insure high levels.Experimental economics, risk aversion, risk attraction, income risks, Leex

Do the Wealthy Risk More Money? An Experimental Comparison.

Are poor people more or less likely to take money risks than wealthy folks? We find that risk attraction is more prevalent among the wealthy when the amounts of money at risk are small (not surprising, since ten dollars is a smaller amount for a wealthy person than for a poor one), but, interestingly, for the larger amounts of money at risk the fraction of the nonwealthy displaying risk attraction exceeds that of the wealthy. We also replicate our previous finding that many people display risk attraction for small money amounts, but risk aversion for large ones. We argue that preferences yielding “risk attraction for small money amounts, together with risk aversion for larger amounts, at all levels of wealth,” while contradicting the expected utility hypothesis, may be well-defined, independently of reference points, on the choice space.risk attraction; risk aversion; wealth; experiments

Imitation of succesful behavior in Cournot markets

In an experimental standard Cournot Oligopoly we test the importance of models of behavior characterized by imitation of succesful behavior. We find that the players appear to the rather reluctant to imitate.Oligopoly, cournot, bounded rationality, spite effect, Leex