About the role, in older days, of econometrics in quantitative economics*

Coming after recent contributions on the history of econometric ideas, my testimony as an old econometrician first touches on the early relations between quantitative economics and economic theory, both in France during the thirties and around the Cowles Commission in Chicago during the late forties. The main part of the paper aims at showing how essential roles were later played by the emergence of a system of concepts, and by discussions about the potentials of macroeconometric models for testing theories, forecasting trends or still analysing contemplated policies.