All of them

3. (30 points) A country with a closed economy discovers large oil deposits. Assume that the only effect of this discovery is an increase in the expected future marginal product of capital. a. Use the capital market diagram (user cost and MPK vs capital stock) to show the effect on the equilibrium level of capital stock. b. Use desired investment/ savings diagram (with the real interest rate on the vertical axis) to analyze the effects on national saving, investment, and the real interest rate