SSOs: Current Policy Issues and Empirical Evidence

Despite the increasing importance of and huge growth in SSOs and the flurry of research on the economics of SSOs in the last decade, no comprehensive review of the literature exists. Such an undertaking is beyond the scope of this paper. Here, we address a more modest goal: a selective review focusing on current policy issues regarding SSOs and empirical evidence on the performance of SSOs. A key part of the analysis here focuses on what light the empirical work on SSOs can shed on SSO performance.