Agricultural price volatility is "bad". But where does it come from? Remedies are completely different for "endogenous" or "exogenous" fluctuations. The recent crisis seems to indicate that exogenous remedies have been applied to endogenous fluctuations.

This phd contributes to the definition of efficiency measures and productivity indicator, in the microeconomic theory. It presents theoretical and empirical contributions. Firstly, this phd develops a review on standard measures of efficiency and productivity. It is shown that the directional...