Employer matching of employee 401(k) contributions can provide a powerful incentive to save for retirement and is a key component in pension-plan design in the United States. Using detailed administrative contribution, earnings, and pension-plan data from the Health and Retirement Study, this...

Often, a relatively small group of trades causes the major part of the trading costs on an investment portfolio. For the equity trades studied in this paper, executed by the world's second largest pension fund, we find that only 10% of the trades determines 75% of total market impact costs....