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...

We use an experiment to estimate the effect of the SEC's Summary Prospectus, which simplifies mutual fund disclosure. Our subjects chose an equity portfolio and a bond portfolio. Subjects received either statutory prospectuses or Summary Prospectuses. We find no evidence that the Summary...