I recently stumbled across yet another paper setting out to empirically assess whether attorneys generate independent value for their clients. Put slightly differently--and in the words of the author, Erica Hashimoto (Georgia), the paper tests the long-held assumption that "there is no good reason for a [criminal] defendant to choose self-representation, and those who make that choice are either mentally ill or foolish." Hashimoto's findings run against conventional wisdom.
Although in terms of research design and execution this paper is perhaps not as methodologically sophisticated as the Lederman tax court paper, Hashimoto's largely descriptive account is interesting and contributes to a foundation for future work. (Orin Kerr provides additional commentary on the Hashimoto paper here.)