Part 1 is a comparative analysis showing the effects of monetary and fiscal policy on the economy. Real-wage rigidity in the labour market is shown to have important consequences for the working of both types of policy, because it conditions the economy’s response to tax changes. Part 2 presents an econometric model which combines consistent stock-flow accounts with a full range of expectational effects. Part 3 presents an innovative technique for solving rational expectations models with the need for arbitary terminal conditions.