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...

We study the relationship between past returns on a company's stock and the level of investment in that stock by the participants in that company's 401(k) plan. Using data on 94,191 plan participants, we analyze several different decision points: the initial fraction of savings allocated to...

We assess the impact on savings behavior of several different 401(k) plan features, including automatic enrollment, automatic cash distributions, employer matching provisions, eligibility requirements, investment options, and financial education. We also present new survey evidence on individual...

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...

We analyze the impact of a Web-based trading channel on the trading activity in two corporate 401(k) plans. Using detailed data on about 100,000 participants, we compare trading growth in these firms to growth for a sample of firms without a Web channel. After 18 months of access, the inferred...

Defaults can have a dramatic influence on consumer decisions. We identify an overlooked but practical alternative to defaults: requiring individuals to make an explicit choice for themselves. We study such "active decisions" in the context of 401(k) saving. We find that compelling new hires to...

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 study a retirement savings plan with a default contribution rate of 12% of income, which is much higher than previously studied defaults. Twenty-five percent of employees had not opted out of this default 12 months after hire; a literature review finds that the corresponding fraction in plans...

If individuals have self-control problems, they may take up commitment contracts that restrict their spending. We experimentally investigate how contract design affects the demand for commitment contracts. Each participant divides money between a liquid account, which permits unrestricted...

What is the socially optimal level of liquidity in a retirement savings system? Liquid retirement savings are desirable because liquidity enables agents to flexibly respond to pre-retirement events that raise the marginal utility of consumption. On the other hand, pre-retirement liquidity is...