This week, my young fellow colleague Cyril Benoit, lecturer in Political Sciences, and me, are going to present at the International Health Policy Conference to be held at London School of Economics our working paper entitled: “Orphan Drugs: why US   approves more than the EU? “. Indeed, the number of orphan drug designations (as well as OD market approvals) application approvals in Europe is still significantly lower than in it is the US. The goal of this paper is to explain this discrepancy, by providing empirical, quantitative materials on the basis of an analysis of all of the decisions delivered by the EMA for this category of drugs. 3 explanations have been explored and will be discussed: (i) – Effects of bureaucratic politics at the EMA, (ii) engagement from rent-seekers Big Pharmas, (iii) Consequences of the structure of tax-credits (US vs. EU).