The European emissions trading scheme (EU ETS) has an efficient and effective market design that risks being undermined by three interrelated problems: the approach to allocation; the absence of a credible commitment to post-2012 continuation; and concerns about its impact on the international competitiveness of key sectors. This special issue of Climate Policy explores these three factors in depth. This policy overview summarizes key insights from the individual studies in this issue, and draws overall policy conclusions about the next round of allocations and the design of the system for the longer term.