[eng] Crucial divergences emerge between the theoretical concepts of major variables and their empirical counterparts. We have come to recognize some of the problems in using current values in place of expectations of the future. Futher difficulties abound in our measures of income and product,...

[eng] Contemporary Keynesian theory sees the unemployment rate as driven by shocks to aggregate demand and ply, and attracted back to some equilibrium, or natural, rate. The latter is exogenous : either autonomous or, if path-dependent, predetermined. Fiscal stimuli to demand are expansionary...