Working paper available from SSRN.com for $5. Excerpt: [S]ome states have proposed a guarantee mechanism to help protect DC plan participants. One such guarantee takes the form of an option to buy back the DB benefit. This paper develops a theoretical framework to analyze the option design and how employee characteristics influence the option's cost. We illustrate the potential magnitude of these costs with a buy-back option embedded in a recent reform enacted by the state of Florida ...