Though millions of US workers have 401(k) plans, few studies evaluate participant investment performance. Using data on over 1,000 401(k) plans and their participants, we identify key portfolio investment inefficiencies and attribute them to offered investment menus versus individual portfolio...

This paper explores the risks and benefits of holding company stock in employer-sponsored defined contribution (DC) retirement plans. We address three questions: (1) What is the role and function of company stock in such plans? (2) Who might be affected by enhanced portfolio diversification in...

Tax-qualified retirement plans seek to promote saving for retirement, yet most employers permit pre- retirement access by letting 401(k) participants borrow plan assets. This paper examines who borrows and why, and who defaults on their loans. Our administrative dataset tracks several hundred...

We develop a comprehensive model of 401(k) pension design that reflects the complex tax, savings, liquidity and investment incentives of such plans. Using a new dataset on some 500 plans covering nearly 740,000 workers, we show that employer matching contributions have only a modest impact on...