5. Algebra of the income-expenditure model Consider a small economy that is closed to trade, so its net exports are equal to zero. Suppose that the economy has the following consumption function, where C is consumption, Y is real GDP, I is investment, G is government purchases, and T is for net taxes: C = 40 +0.5 X ( Y -T) K Suppose G = $165 billion, / = $50 billion, and T = $10 billion. Given the consumption function and the fact that, in a closed economy, total expenditure can be calculated as Y = C + / + G, the equilibrium output level is $ billion. Suppose the government purchases are increased by $150 billion. The new equilibrium level of output will be equal to $ billion. Based on the effect of the change in government purchases on equilibrium output, you can tell that this economy's spending multiplier is equal to