Assume that the money demand is L = 0.2Y, the money supply is M = 200, consumption C = 90+ 0.8YD, tax revenue T = 50, investment I = 140-5R, and government expenditure G = 50.

(1) Equilibrium of income, interest rates and investments;

(2) If, other things being equal, government expenditure G increases by 20, what happens to income, interest rates, and investment?

(3) Is there a "crowding out effect"?