We evaluate why individuals invest in high-fee index funds. In our experiments, subjects each allocate $10,000 across four S&P 500 index funds and are rewarded for their portfolio's subsequent return. Subjects overwhelmingly fail to minimize fees. We reject the hypothesis that subjects buy...

We assess the impact of 401(k) plan design on four different 401(k) savings outcomes: participation in the 401(k) plan, the distribution of employee contribution rates, asset allocation, and cash distributions. We show that plan design can have an important effect on all of these savings...

We show that individual investors over-extrapolate from their personal experience when making savings decisions. Investors who experience particularly rewarding outcomes from 401(k) saving-a high average and/or low variance return-increase their 401(k) savings rate more than investors who have...

Economic theory predicts that an unexpected wealth windfall should increase consumption shortly after the windfall is received. We test this prediction using administrative records on over 40,000 401(k) accounts. Contrary to theory, we estimate a negative short-run marginal propensity to consume...

Defaults often have a large influence on consumer decisions. We identify anoverlooked but practical alternative to defaults: requiring individuals to make explicitchoices for themselves. We study such ?active decisions? in the context of401(k) saving. We find that compelling new hires to make...

In the last several years, many employers have decided to automatically enroll their new employees in the company 401(k) plan. Using several years of administrative data from three large firms, we analyze the impact of automatic enrollment on 401(k) participation rates, savings behavior, and...