AgriBio3 PEPP « Rôle de la Performance Economique des exploitations et des filières, et des Politiques Publiques, dans le développement de l’AB »Using original survey data from France we study the importance of technical efficiency as a potential determinant of farm conversion to organic farming in the dairy sector. We run a two-stage analysis. In the first stage we calculate technical efficiency of farms when they were conventional (including organic farms before they convert) as well as technical efficiency change indices, using Data Envelopment Analysis and correcting for sample bias with Simar and Wilson’s bootstrapping procedure. In the second stage, we estimate a Probit model to explain the decision of farmers to convert to organic fa...