Using panel data for nearly 1,000 companies during 1991 to 2000, this paper documents that the average share of participant's discretionary 401(k) contributions in company stock was almost 20 percent, and then relates this share to plan design features and firm financial characteristics. We find...

We use a two-year panel of individual accounts in an Samp;P 500 index mutual fund to examine the trading and investment behavior of more than 91 thousand investors who have chosen a low-cost, passively managed vehicle for savings. This allows us to characterize investors' heterogeneity in terms...