20 March 2017The land sparing versus land sharing debate has already had a significant history and was particularly active during the last decade. Studies carried out mostly by ecologists and agronomists have clarified a number of issues related to best land use strategies in different landscapes, establishing that the best strategy depends first on the response of biodiversity to anthropogenic pressures, and can vary with the spatial scale of the analysis. We argue that the first contribution of an economist’s perspective is to place the idea of social efficiency, i.e., the improvement in human welfare from limited resources, at the heart of discussions and models concerning the food/biodiversity nexus. The purpose and meaning of economic approaches, whether incorporated into biophysical analyses or based on their results, is to identify and understand the logic and behaviour of agents and their impact on land use. We highlight some significant results derived from modelling work. In particular, it is shown that the assumption of fixed production target used in many works is unrealistic. We put into perspective recent work that analysed the effects of price changes and the impact of agricultural markets on land use. We conclude on the importance of integrating the economic mechanisms that guide individual and collective behaviours, in the design of local policy mix between land sparing and land sharing.