[Excerpt] The 1984 publication of Richard Freeman and James Medoff’s What Do Unions Do? was a landmark event in research on labor unions. It challenged existing negative economic conceptions of the role of unions by presenting a two-faced model of unionism in which the negative monopoly face of unions was counter-balanced by a positive collective voice face. For those in the labor movement, this book became a powerful source of academic support for their value to society and the economy. Among academics, WDUD was equally influential, as it encouraged a renewed, more data-intensive and methodologically sophisticated approach to research on unions. In the present volume, James Bennett and Bruce Kaufman have brought together an impressive set of scholars to review the progress in research on unions in the two decades since the publication of WDUD. The volume, which originated as a series of special issues in the Journal of Labor Research, serves both as an evaluation of the arguments presented in WDUD in light of subsequent research and more generally as an overview of the current state ofresearch on unions. On both of these levels, the book is a tremendous success, albeit with certain limitations. It will be useful for anyone wanting a sourcebook on recent research on unions. Although not quite as accessible to non-specialist readers as WDUD itself, the volume should be particularly useful to academic researchers and to public policy and practitioner experts in the labor area. It will also provide a useful set of readings for graduate courses on labor unions, particularly those focusing on the economic effects of unions.