1. Department of Economic History, Institutions, Policy and World Economy; University of Barcelona; Diagonal Avenue 690 08034 Barcelona Spain
2. Department of Economics; University of Girona; Montilivi Campus 17003 Girona Spain
3. Department of Geography; University of the Balearic Islands; Valldemossa Road km 7.5 07122 Palma de Mallorca Spain
4. University of the Balearic Islands and technical assistant at the Organic Farming Association of Mallorca (APAEMA); Spain