In this paper we explore new avenues of analysis on the thorny issue of the impact of participatory technology assessment (PTA). We apply Qualitative Comparative Analysis to data abstracted from a series of detailed country case studies of policy making on xenotransplantation to explore what factors are decisive for policy outcomes. Contrary to our expectations that PTAs would contribute to restrictive policy outcomes, we find that this is not the case and that a combination of politicisation and public vigilance is pivotal to explaining policy outcomes. Further, our analysis was symmetrical in attempting to account for both permissive and restrictive policies. We conclude that the paper makes both a substantial and a methodological contribution to the literature on public participation in technology assessment and policy making.
