Automated model linkages: the example of CAPRI

Increasing demand for policy impact assessment regarding social,economic and environmental aspects asks for combined applicationof different models and tools. The paper discusses concepts andchallenges in linking models, taking CAPRI (Common AgriculturalPolicy Regionalised Impact) model as an example. CAPRI combinesdifferent economic models, spatial downscaling and interfaces tobio-physical components. 250 non-linear regional programmingmodels with econometrically estimated costs functions cover theEU-27, Norway and Western Balkans. They are consistently linked toa spatial globally closed trade model, covering 60 countries / countryblocks and 50 primary and secondary agricultural products. Thelink is based on sequential calibration: the market models pricesdrive the programming models whereas its supply and feed demandcurves are calibrated to the programming models’ results, iterativelyrepeated to convergence. CAPRI integrates projection results fromother model systems in the baseline generation and calibrates thesupply models to econometric estimations or the supply responsefrom other models as in SEAMLESS. The spatial down-scalingcomponent breaks down the regional EU-27 results regarding croppingshares, crop yields, animal stocking densities and fertilizerapplication rates to about 140 000 1x1 km pixel cluster and linksthese results to a statistical meta model of the bio-physical modelDNDC.