José De Sousa 

Agriculture, Trade and Biodiversity

Jean-Marc Bourgeon (INRAE and Ecole Polytechnique) and José De Sousa (U. Paris-Saclay, RITM and LIEPP Sciences Po)

 

Abstract: Thanks to an increasing openness to trade over the past decades, farmers around the world have specialized their production on the most productive crops. However, the more specialized the agriculture, the greater the number of pests that use the selected crops as a host and the greater the probability of infection. The decrease in crop biodiversity has thus led to a massive use of agrochemicals and created negative externalities.

We explore the trade-off between specialization, biodiversity and pesticide use by incorporating ecological mechanisms into a Ricardian model of trade specialization. The probabilistic model allows us to specify crop survival and productivity as a function of diversity. In particular, we highlight the role of biotic and abiotic factors that affect crop production.

Guided by the model and using detailed and geo-localized agriculture data, we then estimate the impact of biodiversity on crop productivity. We quantify biodiversity using indices from the ecological literature based on species richness (i.e. total number of species) and relative abundance. These indices reflect the fact that biodiversity is high when the total number of species is large and their relative abundance distribution is homogeneous. Our preliminary results confirm that diversity has a positive and significant impact on the quantities produced.