Final answer:
The concepts of real GDP and aggregate demand are key elements in macroeconomic analysis. The Keynesian cross model depicts how equilibrium real GDP is determined in the economy, and the rational expectations theory might impact the efficacy of monetary policy. To find the equilibrium, one needs to equalize the aggregate expenditure with real GDP.
Step-by-step explanation:
Within the context of macroeconomics, and specifically in relation to the Keynesian cross model and the concepts of real GDP and aggregate demand, there are several important facets to consider when analyzing the effects of monetary policy and finding economic equilibrium.
Firstly, in the Keynesian framework, an increase in the money supply can initially lead to a higher level of real GDP, indicating a boost in aggregate demand. However, according to the rational expectations theory, agents in the economy anticipate future policy actions and adjust their behavior accordingly, which might result in a different outcome than the traditional Keynesian prediction.
To find the economic equilibrium or the level of real GDP that the economy will reach, the Keynesian cross model approach involves setting aggregate expenditures equal to real GDP. This is demonstrated by the algebraic expression AE = C + I + G + X - M, where C is consumption, I is investment, G is government spending, X is exports, and M is imports. Calculating the equilibrium level of output then involves solving for Y when AE equals Y.