時間割引と肥満(消費者心理を科学する-認知心理学と行動経済学の接点-,2008年度第2回フォーラム)

抄録

Based on Ikeda et al. (2009), I discuss whether interpersonal differences in body mass are related to those in time discounting and its anomalies reported in behavioral economics. The effects of time discounting on body mass index (BMI) and the probabilities of being obese, severely obese, and underweight are detected by incorporating three properties regarding time discounting: (1) impatience, measured by the level of the respondents' discount rates; (2) hyperbolic discounting, where discount rates for the discounting of immediate future choices are higher than those for distant future choices; and (3) sign effects, wherein future negative payoffs are discounted at a lower rate than are future positive payoffs. The results imply that body mass is determined as an outcome of intertemporal decision makings, so that it can be affected by controlling in the intertemporal structure of medical care costs and the price of a calorie.