Given the following variables in the open economy aggregate expenditure model, autonomous consumption (C0) = 800, autonomous investment (I0) = 600, government spending (G0) = 700, export spending (X0) = 400, autonomous import spending (M0) = 700, taxes (TP) = 200, marginal propensity to consume (c1) = 0.75, marginal propensity to invest (i1) = 0.2, and marginal propensity to import (m1) = 0.15.
a. Calculate the equilibrium level of income for the open economy aggregate expenditure model. (Show all your steps carefully.)
b. If there is a decrease in the marginal propensity to consume from 0.75 to 0.65, calculate the new equilibrium level of income and the value of the multiplier. (Again, show all your steps carefully.)