Agents with more experience make better choices. We measure learning dynamics using a panel with four million monthly credit card statements. We study add-on fees, specifically cash advance, late payment, and overlimit fees. New credit card accounts generate fee payments of $15 per month....

We derive the first closed-form optimal mortgage refinancing rule. The expression is derived by using the Lambert-W function to solve a tractable class of mortgage refinancing problems. We calibrate our solution and show that our quantitative results closely match those reported by researchers...

In cross-sectional data sets from ten credit markets, we find that middle-aged adults borrow at lower interest rates and pay fewer fees relative to younger and older adults. Fee and interest payments are minimized around age 53. The measured effects are not explained by observed risk...

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...

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...

Default options have an enormous impact on household choices.' Defaults matter because opting out of a default is costly and these costs change over time, generating an option value of waiting. In addition, people have a tendency to procrastinate. We develop a theory of optimal defaults based on...

Intertemporal tradeoffs play a key role in many personal decisions and policy questions. We describe models of intertemporal choice, identify empirical regularities in choice, and pose new questions for research. The focus for intertemporal choice research is no longer whether the exponential...

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...

We review research that measures time preferences - i.e., preferences over intertemporal tradeoffs. We distinguish between studies using financial flows, which we call "money earlier or later" (MEL) decisions and studies that use time-dated consumption/effort. Under different structural models,...