Long-run Effective Demand in the US Economy: An Empirical Test of the Sraffian Supermultiplier Model

The Sraffian supermultiplier is a model of demand-led growth that stresses the importance of the autonomous components of aggregate demand (exports, public spending and autonomous consumption). This article tests empirically some major implications of the model employing macroeconomic data for the United States. In particular, we study the long-run relation between autonomous demand and output through cointegration analysis. The results suggest that autonomous demand and output are cointegrated and that autonomous demand exerts a long-run effect on output. There is also some evidence of simultaneous causality, especially in the short-run. Movements in autonomous demand and in the investment share are also found to be positively related, with Granger-causality going from Z to I/Y.