Essays on food price volatility : some perspectives on trade and information

The 2007-08 and 2010-11 food crises, and especially their consequences on the poorest households, have led to a renewed interest for food price stabilisation. This thesis investigates three issues about food price volatility: the role of state trading enterprises for food security; the impact of information accuracy regarding natural or economic shocks on food price variations; and the consequences of increased transparency on international markets following the G20 summit of 2011. We derive public policies conclusions regarding trade policies and improvements of information systems. We also bring forward a methodological tool that is hardly applied to agricultural economics: imperfect information models. The applications presented in this thesis prove the relevance of this tool for analysing many agricultural issues.