Terrorisme à grande échelle partage de risques et politiques publiques

The terrorist attacks of September 11,2001 against the United-States made a great impact on both insurance/reinsurance industry in the world ? as the most costly event never occurred in the insurance history ? and governmental responsabilities. Because of its particular configuration, such a tragedy made of terrorism a new source of large-scale extreme risks. From this date, and in a catastrophic risk coverage?s perspective, terrorism is often compared with other devasting events like natural disasters. We show in this article that terrorism presents, however, several singularities in an insurance point of view and is actually much more complex to be managed than the natural hazards, even being catastrophic: negative externalities of auto-protection; a dynamic uncertainty associated with the risk, a very specific distribution of information on risk as well as the influence of government decisions on terrorism activities. Taking into account those singularities, the market reactions to 9/11 and considering the role of governments, several key questions arise: Who should pay for the consequences of terrorist attacks? How financing such events? Can one establish ex ante some national mechanisms of extreme risk sharing that would be based upon a necessary public-private partnership? We also discuss the provisory terrorism risk coverage schemes established in 2002 in France and the United States. This article, which is based on the most recent developments on that issue, suggests some elements for response; it presents an analysis in a field of research that has been relatively underdealt with by the French economic literature.