27 pages. Excerpt: In this paper, we identify a sizeable group of employees whose observable choice set in an important retirement savings vehicle, the 401(k), includes actions that are clearly precluded by normative economic theory. These individuals, who are over 59½ years old, have their 401(k) contributions matched by their employer; that is, for every dollar they contribute up to a certain threshold, their employer will make an additional proportional contribution.