The advent of the Roth 401(k) significantly expanded opportunities for tax-preferred retirement saving, but at the same time it created much confusion for individual savers regarding whether to save in the form of pre-tax or Roth dollars. The financial community's conventional wisdom is based on...

We evaluate retirement savings adequacy using a large panel of U.S. workers with a 401(k) account. We model medical expenditures, longevity, investment risk, and the likelihood of withdrawals due to hardship, job separation, and reaching age 59 1/2. Based on their current account balances,...