Measuring Decreasing and Increasing Impatience
提出DI指数，独立于效用和不耐烦水平测量不耐烦程度的变化，用于检验不同贴现模型，实验发现不耐烦变化与日常自我控制问题无显著相关。
Many studies show that time preference data from experiments and surveys are related to field behavior. Time preference measures in these studies typically depend simultaneously on utility curvature, the level of impatience, and the change in the level of impatience. Thus, these studies do not allow one to establish which of these three components drive(s) the field behavior of interest. Of these components, the change in the level of impatience is theoretically thought to be the main driver of time inconsistencies and self-control problems. To test this theoretical presumption, one has to measure the change in the level of impatience independently from utilities and levels of impatience. This paper introduces a measure of the degree of decreasing impatience, the DI-index. It measures the change of impatience independently from the level of impatience and independently from utility. It can also be used to test various discounting models. An experiment finds no correlation between the degree of decreasing impatience and self-reported self-control problems in daily life, suggesting that changing impatience is not the sole driver of self-control problems. Data and the supplementary material are available at https://doi.org/10.1287/mnsc.2017.3015 . This paper was accepted by Manel Baucells, decision analysis.