In the context of a long run agricultural outlook on behalf of the European Environmental Agency a new methodology has been developed to systematically integrate external forecasts into a quite detailed agricultural sector model. External forecasts usually provide estimates for the exogenous variables in modelling work and frequently they are also used for comparisons and potential reassessment of empirical specifications. The innovative characteristic of this study is that expert forecasts have been used to specify parameter changes expressing structural change affecting behavioural functions. The outlook was therefore set up as a simultaneous estimation and forecasting effort which permitted to integrate various, usually contradictory expert forecasts subject to the equations of the sector model.