Benefits and costs of biodiversity in agricultural public policies

Abstract

This paper examines the role played by biodiversity goals in the design of agricultural policies. A bio-economic model is developed with a dynamic and multi-scale perspective. It combines biodiversity dynamics, farming land-uses selected at the micro level and public policies at the macro level based on financial incentives for land-uses. The public decision-maker identifies optimal subsidies or taxes with respect to both biodiversity and budgetary constraints. These optimal policies are then analysed through theirprivate,publicandsocialcosts.Themodeliscalibratedandappliedtometropolitan France at the small agricultural region scale, using common birds as biodiversity metrics. First results relying on optimality curves and private costs stress the bioeconomic trade-offbetween biodiversity andeconomic scores. Incontrast,the analysis ofpubliccostssuggeststhataccountingforbiodiversitycangenerateasecondbenefitin terms of public budget. Social costs defined as the sum of private and public costs also show possible bio-economic synergies.