We develop a Keynesian cross analysis with a dynamic optimization setting that explains long-run stagnation caused by aggregate demand deficiency. We show that an increase in government purchases boosts GDP through a multiplier process, but the implication is quite different from the...

Keynesian theory suggests that a reduction in government expenditure has a negative effect on private demand and therefore on output. Contrary, neoclassical theory argues that reduced public expenditure makes room for an expansion of the private sector and thus has a stimulating effect on the...