Risk Aversion and the Subjective Time Discount Rate: A Joint Approach

This discussion paper led to a publication in the <A HREF="http://www.sciencedirect.com/science/article/pii/S0167268109000109">'Journal of Economic Behavior & Organization'</A>, 2009, 70(1-2), 374-388.<P> In this paper we analyze a large sample of individual responses to six lottery questions. Wederive a simultaneous estimate of risk aversion γ and the time preference discount rate ρ perindividual. This can be done because the consumption of a large prize is smoothed over a largertime period. It is found that ρ and γ strongly vary over individuals, while they are negativelycorrelated with a correlation coefficient of -.3. Furthermore we explain γ and ρ by income,age, gender, entrepreneurship and an obesity index. Very significant effects are found. If weexplain γ in a simple model where time discounting is ignored, we find completely differentestimates for γ . We conclude that in the case of lotteries with big prizes a simultaneous estimateof γ and ρ is needed in order to avoid misspecification.