This paper aims to explore the Keynesian idea that aggregate demand matters for economic activity, both in the short and long run. To that extent, it discusses the endogeneity of the natural rate of growth, and presents two empirical exercises: the first one tests for unit roots in output for 12...

The theme of unit roots in macroeconomic time series has received a great amount of theoretical and applied research in the last two decades. This paper presents some of the main issues regarding unit root tests, explores some of the implications for macroeconomic theory and policy, and reviews...