Choice-Based Elicitation and Decomposition of Decision Weights for Gains and Losses Under Uncertainty

This Paper reports the results of an experimental parameter-free elicitation and decomposition of decision weights under uncertainty. Assuming cumulative prospect theory, utility functions were elicited for gains and losses at an individual level using the trade-off method. Then decision weights were elicited using certainty equivalents of uncertain two-outcome prospects. Furthermore, decision weights were decomposed using observable choice instead of invoking other empirical primitives as in the previous experimental studies. The choice-based elicitation of decision weights allows for a quantitative study of their characteristics, and also allows, among other things, to confront the sign-dependence hypothesis with observed choice under uncertainty. Our results confirm concavity of the utility function in the gain domain and bounded sub-additivity of decision weights as well as choice-based subjective probabilities. We also find evidence of sign-dependence of decision weights.