摘要：We examine the role of changing mortality in explaining the rise of retirement over the
course of the 20th century. We construct a model in which individuals make labor/leisure
choices over their lifetimes subject to uncertainty about their date of death. In an envi-
ronment in which mortality is high, an individual who saved up for retirement would face
a high risk of dying before he could enjoy his planned leisure. In this case, the optimal
plan is for people to work until they die. As mortality falls, however, it becomes optimal
to plan, and save for, retirement. We simulate our model using actual changes in the
US life table over the last century, and show that this “uncertainty effect” of declining
mortality would have more than outweighed the “horizon effect” by which rising life ex-
pectancy would have led to later retirement. One of our key results is that continuous
changes in mortality can lead to discontinuous changes in retirement behavior.
