In the simple Keynesian model with no government and foreign sectors, suppose that initially the economy is in equilibrium at an output of $10 trillion with a marginal propensity to consume of 0.8. If investment spending increases by $0.5 trillion, what is the new equilibrium output level?
- $10.5 trillion
- $12.5 trillion
- $12.0 trillion
- $10.8 trillion