IS Curve in Open Economy Framework Quiz: Output Demand

The IS curve in an open economy represents all combinations of national income and the interest rate at which total planned spending equals total output. In an open economy, spending includes consumption, investment, government expenditure, and net exports. The addition of net exports to the standard closed economy IS relationship means that exchange rate changes can shift the IS curve, making the open economy version more sensitive to external conditions.

The answer is True. A depreciation of the domestic currency makes exports cheaper for foreign buyers and imports more expensive domestically, increasing net exports. Since net exports are a component of aggregate demand in the open economy, the rise in net exports increases total spending at every interest rate level. This shifts the IS curve to the right, reflecting a higher level of income consistent with goods market equilibrium at each possible interest rate.

The IS curve slopes downward because a higher interest rate reduces aggregate demand through two channels in an open economy. First, higher rates discourage investment by raising the cost of borrowing. Second, in a flexible exchange rate setting, higher rates attract capital inflows that appreciate the currency, reducing net exports. Both effects reduce output, so higher interest rates are associated with lower equilibrium income, giving the IS curve its negative slope.

The IS curve shifts leftward whenever aggregate demand falls at every level of the interest rate. In an open economy, this can happen when the government cuts spending, raises taxes, or when net exports decline due to currency appreciation or reduced foreign income. Each of these reduces total planned spending at every interest rate level, shifting the entire IS curve to the left and lowering the equilibrium income level for the economy.

The IS curve shifts rightward when aggregate demand increases. This occurs when government spending rises, when currency depreciation improves net exports by making domestic goods cheaper abroad, and when higher foreign income increases the demand for domestic exports. A rise in domestic interest rates does not shift the IS curve rightward; rather, it is a movement along the IS curve that lowers output by discouraging investment and potentially appreciating the currency.

The answer is False. The IS curve in an open economy is generally flatter than in a closed economy, not steeper. Net exports add an additional channel through which interest rate changes affect output. When interest rates change, investment responds as in a closed economy, but the exchange rate also adjusts, affecting net exports. This additional transmission mechanism means that output responds more strongly to interest rate changes, making the IS curve flatter.

When the world interest rate rises, capital flows out of the domestic economy seeking higher returns abroad, causing the domestic currency to depreciate. The depreciation makes exports more competitive and reduces imports, improving net exports. Since net exports are part of aggregate demand in the open economy, this improvement shifts the IS curve to the right. The world interest rate thus indirectly influences the domestic IS curve through the exchange rate channel.

In the open economy IS curve, net exports are a component of total spending and respond to both income and the exchange rate. A currency depreciation that improves net exports shifts the IS curve right, and a worsening trade balance shifts it left. Because net exports provide an additional link between interest rates, exchange rates, and output, they also influence the steepness of the IS curve, generally making it flatter than the closed economy version.

The answer is True. Consumer confidence drives household spending decisions. When confidence falls, households reduce consumption at every income level, decreasing aggregate demand. Since the IS curve represents combinations of income and the interest rate where the goods market is in equilibrium, a fall in demand means equilibrium output is lower for every interest rate. This shifts the IS curve leftward, signaling that goods market equilibrium requires a lower level of income or a lower interest rate.

The IS curve slopes downward because higher interest rates reduce both investment and net exports via currency appreciation. It shifts rightward when fiscal policy expands or net exports improve due to depreciation or higher foreign income. Its position is also influenced by the exchange rate and foreign economic conditions, all of which affect aggregate demand. The claim that a rightward shift always reflects a fall in aggregate demand is incorrect; a rightward shift reflects a rise in demand.

The key distinction is that the open economy IS curve includes net exports as an additional component of aggregate demand and is sensitive to the exchange rate. A change in the exchange rate affects net exports and therefore shifts the IS curve in a way that has no equivalent in a closed economy. This extra channel makes the IS curve in the open economy flatter, because output responds more fully to interest rate changes through both the investment and the trade balance channels.

The answer is True. Foreign income affects domestic net exports because higher foreign income increases demand for domestic goods sold abroad. When foreign income rises, export revenues increase, boosting aggregate demand. This improvement in net exports shifts the IS curve rightward without any change in domestic policy. Similarly, a fall in foreign income reduces export demand and shifts the IS curve leftward, demonstrating that the open economy IS curve is sensitive to external economic conditions.

A reduction in government spending directly reduces aggregate demand, since government expenditure is a component of total planned spending in the goods market. For every level of the interest rate, the equilibrium level of output consistent with goods market balance is now lower. This shifts the entire IS curve to the left. The shift is not a movement along the curve but a change in the relationship between income and the interest rate throughout the entire schedule.

The IS curve shifts in response to changes in aggregate demand components that are independent of the interest rate. These include fiscal policy changes, exchange rate movements that alter net exports, and changes in foreign income that affect export demand. A change in the domestic money supply is a monetary policy action that shifts the LM curve, not the IS curve, since it operates through the money market rather than through the goods market directly.

When the IS curve shifts rightward with an unchanged LM curve, the two curves intersect at a new point that features both higher output and a higher interest rate. The rightward IS shift reflects higher aggregate demand, which pushes equilibrium income up. However, the higher income increases money demand, pushing the interest rate up along the fixed LM curve. The final result is higher output accompanied by a somewhat higher interest rate compared to the original equilibrium.