Unit 6: Open Economy—International Trade and Finance

Trade, Specialization, and Net Exports in the Macroeconomy

An open economy interacts with the rest of the world through trade in goods and services, financial flows (buying and selling assets), and currency exchange. In AP Macroeconomics, the goal is to understand how international transactions affect measured output, financial positions, and key macro variables like interest rates, aggregate demand, and inflation.

Why countries trade (even when one is “better at everything”)

Countries trade because of comparative advantage: specialization is based on opportunity cost, not absolute productivity. Even if one country has an absolute advantage in producing all goods, both countries can still gain if each specializes in what it produces at lower opportunity cost and then trades.

Imports, exports, and the GDP accounting framework

Using the expenditure approach:

Y = C + I + G + (X - M)

Exports and imports affect GDP through net exports:

NX = X - M

Imports are subtracted not because they are “bad,” but because C, I, and G include spending on both domestic and foreign-produced items. Subtracting M removes the foreign-produced portion so GDP reflects domestic production only.

Trade balance, trade deficits, and what they do (and don’t) mean

The trade balance is typically exports minus imports of goods and services (often aligned with net exports). A trade deficit means imports exceed exports, so NX < 0. This is not automatically a sign of weakness. A deficit can coexist with strong domestic investment (financed by foreign investors), strong domestic consumption, and a relatively strong currency (which makes imports cheaper and exports harder to sell).

Example: interpreting NX inside GDP

Suppose a country has consumption spending that includes 200 of imported consumer goods, investment spending that includes 100 of imported machinery, exports of 250, and total imports of 400. Net exports are:

NX = 250 - 400 = -150

That negative value reduces measured GDP relative to what C + I + G alone would suggest because part of the spending was on foreign production.

What can cause net exports to change?

Net exports change when exports or imports change. Core drivers include income levels at home and abroad, relative prices (including tariffs and inflation differences), and exchange rates.

Exam Focus
  • Typical question patterns
    • Compute NX and interpret how it affects GDP using Y = C + I + G + (X - M).
    • Explain why imports are subtracted in GDP even though they are included in consumption/investment/government spending.
    • Predict how changes in domestic income, foreign income, or the exchange rate affect exports, imports, and NX.
  • Common mistakes
    • Treating imports as “always bad” rather than recognizing GDP is a measure of domestic production.
    • Forgetting that C includes imported consumer goods and I can include imported capital goods.
    • Confusing a trade deficit with government budget deficits.

Balance of Payments Accounts and the Circular Flow of Dollars

A balance of payments statement is a summary of payments received from foreign countries and payments sent to foreign countries over a period of time. It is an accounting record of international transactions and helps explain whether a country is earning from abroad or financing domestic spending by borrowing from abroad or selling assets.

Current account (CA)

The current account records flows of goods, services, and income. It includes:

  • trade in goods and services (exports and imports)
  • investment income (interest, dividends) received from abroad and paid to foreign investors
  • unilateral transfers (one-way transfers like gifts or remittances)

A current account surplus means net inflows from these current transactions; a current account deficit means net outflows.

Example (investment income): If a Canadian receives dividends from an American corporation or interest from a U.S. Treasury bill, those dollars are sent out of the United States and recorded in the current account as an income payment to foreigners.

A deficit balance in the current account means the United States sent more dollars abroad than the foreign currency it received in current transactions.

Capital (financial) account (FA)

The capital (or financial) account records the flow of investment in real or financial assets between a nation and foreigners, such as stocks, bonds, bank deposits and loans, and direct investment (building factories, buying businesses).

  • If foreigners buy domestic assets, financial capital flows into the country.
  • If domestic residents buy foreign assets, financial capital flows out of the country.

Examples (capital inflows): If a Swedish firm buys a manufacturing facility in Idaho, or if a Mexican citizen buys a U.S. Treasury bond, it is recorded as an inflow of foreign capital into the United States.

A surplus balance in the financial account means more foreign investment flowed into the United States than U.S. investment flowed abroad.

Official reserves account

The official reserves account describes the central bank’s adjustment of a deficit or surplus in the other accounts by adding to or subtracting from holdings of foreign currencies so that the overall balance of payments is zero.

  • Balance of payments deficit: When adding the current and financial accounts shows more dollars sent out than foreign currency coming in. In this case, the central bank credits the account to balance it.
  • Balance of payments surplus: When more foreign currency is coming in than dollars sent abroad. In this case, the central bank transfers the surplus foreign currency into official reserves.

How the accounts connect: the circular flow of dollars

A powerful way to remember the logic is the circular flow of dollars: dollars Americans send to foreigners are ultimately equal to dollars foreigners send to Americans (either for exports or for U.S. assets).

If Americans import more than they export, the current account moves toward deficit. The foreign recipients of those dollars can use them to buy U.S. exports later or, very commonly, to buy U.S. assets—pushing the financial account toward surplus.

In simplified AP logic (often assuming official reserves are not changing):

CA + FA = 0

When official reserves are included explicitly, the overall balance must still sum to zero because it is an accounting identity:

CA + FA + OR = 0

Example: matching a current account deficit with a financial account surplus

Suppose a country has exports of 600, imports of 800, net income from abroad of 50, and net transfers of negative 20.

  • Net exports: 600 minus 800 equals negative 200.
  • Current account: negative 200 plus 50 minus 20 equals negative 170.

So:

CA = -170

In the simplified setting:

FA = 170

Interpretation: the country financed net current-account spending through a net inflow of foreign financial capital (foreigners purchasing its assets on net), or by reducing its holdings of foreign assets.

Exam Focus
  • Typical question patterns
    • Classify transactions as current account vs financial account (export of services vs foreign purchase of domestic bonds).
    • Given a current account value, infer the financial account value using CA + FA = 0 (simplified).
    • Interpret what a current account deficit implies about net capital inflows.
  • Common mistakes
    • Mixing up goods/services and income flows (current account) with asset purchases (financial account).
    • Thinking “financial account surplus” automatically means the country is healthier; it often means borrowing from abroad or selling assets.
    • Forgetting the accounts are linked (and, when relevant, that official reserves can be used to balance the overall statement).

Foreign Exchange Market: Exchange Rates, Demand & Supply, and Equilibrium

International trade and investment require exchanging currencies. The foreign exchange market (FOREX) is where currencies are bought and sold, and the “price” is the exchange rate.

What an exchange rate is (and why quotations matter)

An exchange rate is the price of one currency in terms of another.

Example: If 2 dollars equal 1 euro, then 1 dollar equals 0.5 euro.

AP problems often define the exchange rate as the price of the domestic currency measured in units of foreign currency, such as “euros per dollar.” Always follow the labels provided.

Appreciation vs depreciation

If the exchange rate is quoted as “foreign currency per unit of domestic currency”:

  • Appreciation means the domestic currency becomes more valuable and the exchange rate rises.
  • Depreciation means the domestic currency becomes less valuable and the exchange rate falls.

Foreign exchange demand

Foreign exchange demand is the quantity of a currency that buyers (domestic and foreign) are willing and able to purchase at various exchange rates. The relationship between the exchange rate and the quantity demanded is inverse: as the exchange rate rises, fewer units of the currency are demanded; as it falls, more units are demanded.

In an AP-style “market for dollars” graph, demand for dollars comes from foreigners who want dollars to buy U.S. goods and services (exports) or U.S. assets.

Foreign exchange supply

Foreign exchange supply is the quantity of a currency that sellers are willing and able to sell at various exchange rates. The relationship between the exchange rate and the quantity supplied is direct: as the exchange rate rises, more units are supplied; as it falls, fewer units are supplied.

In the market for dollars, the supply of dollars comes from Americans supplying dollars to buy foreign goods and services (imports) or foreign assets.

FOREX market equilibrium

Equilibrium occurs when the quantity supplied of the currency equals the quantity demanded at a particular exchange rate. Shifts in demand or supply change the equilibrium exchange rate (appreciation or depreciation) and the equilibrium quantity exchanged.

Graphing note you must use on the exam

It is essential to label axes correctly. If the market is for the dollar, the horizontal axis should be labeled Quantity of dollars. The vertical axis depends on how the dollar is priced; if it is priced as the number of euros needed to buy 1 dollar, the correct label is Euros per dollar (or “Euro price of a dollar”).

A built-in misconception to avoid

A safe rule is: people demand the currency of the country where they want to buy goods, services, or assets. If foreigners want U.S. exports or U.S. bonds, they demand dollars.

Exam Focus
  • Typical question patterns
    • Draw/interpret a foreign exchange market graph given a scenario and show appreciation/depreciation via a shift in demand or supply.
    • Identify whether the currency appreciates or depreciates and explain what happens to exports and imports.
    • Use correct axis labels (especially “Quantity of dollars” and “euros per dollar” style pricing).
  • Common mistakes
    • Reversing who demands which currency.
    • Confusing appreciation vs depreciation because the exchange rate is quoted in an unfamiliar way.
    • Treating the FX market as “only trade” and forgetting that investment flows also shift demand and supply.

Determinants of Exchange Rates (Including Speculation) and Policy Impacts

Exchange rates move because of shifts in currency demand and supply. AP questions repeatedly test a core set of determinants, plus the way monetary and fiscal policy work through interest rates and income to affect exchange rates.

Core determinants that shift demand or supply

A useful checklist is the four common determinants that change the FOREX market: foreign tastes, trade prices, income levels, and real interest rates. In practice, “trade prices” includes relative inflation and any factor that changes relative prices of goods and services.

1) Real interest rates (capital flows)

Higher domestic real interest rates (relative to abroad) make domestic financial assets more attractive. Foreign investors increase demand for the domestic currency to buy those assets, which tends to appreciate the currency. Lower domestic real interest rates tend to reduce foreign demand and can contribute to depreciation.

2) Income levels and relative growth rates

When domestic income rises, spending on imports tends to rise, increasing the supply of domestic currency in FOREX (to purchase foreign currency), which tends to depreciate the domestic currency.

When foreign incomes rise, foreigners often buy more of the domestic country’s exports, increasing demand for the domestic currency and tending to appreciate it.

Example (relative incomes): If Europeans experience economic growth while the United States is in a recession, European buying power rises. Europeans may buy more goods overall, including U.S.-made goods, which increases demand for dollars and tends to appreciate the dollar.

3) Relative prices and relative inflation

If domestic inflation is higher than foreign inflation, domestic goods become relatively more expensive. Foreigners buy fewer exports (lowering demand for the domestic currency) while domestic residents buy more imports (raising supply of the domestic currency). The combined effect tends to depreciate the domestic currency.

Conversely, if the U.S. relative price level is falling (U.S. goods become relatively cheaper), demand for dollars tends to rise and the dollar tends to appreciate.

4) Tastes and preferences

If domestic consumers develop stronger preferences for foreign goods and services, demand for foreign currencies rises, increasing the supply of domestic currency in the FX market and tending to depreciate the domestic currency. If foreign consumers develop stronger preferences for U.S.-made goods (or U.S. assets), demand for dollars rises and the dollar tends to appreciate.

5) Speculation

Currencies can be traded as assets. If investors expect a currency to rise in value, they may buy it now to profit later.

Example (speculation and expected interest rates): If it appears that future interest rates will fall in the United States relative to interest rates in Japan, the yen may look like a better investment. Speculators increase demand for Japanese assets, which appreciates the yen and depreciates the dollar.

Conditions that increase demand for the U.S. dollar (and tend to appreciate it)

The dollar tends to appreciate relative to the euro if:

  • European tastes for American-made goods are stronger.
  • European relative incomes are rising, increasing demand for U.S. goods.
  • The U.S. relative price level is falling, making U.S. goods relatively less expensive.
  • Speculators are betting on the dollar to rise in value.
  • The U.S. relative interest rate is higher, making the United States more attractive for financial investments.

Monetary policy impact on exchange rates

Monetary policy changes interest rates and thereby changes capital flows and the exchange rate.

  • If the central bank practices expansionary monetary policy (decreasing the reserve ratio, decreasing the discount rate, or buying bonds), the money supply rises and interest rates tend to fall. Lower interest rates reduce demand for the domestic currency, so it tends to depreciate. Depreciation makes domestic goods cheaper to foreigners, which tends to raise net exports and shift aggregate demand right.

  • If the central bank practices contractionary monetary policy (increasing the reserve ratio, increasing the discount rate, or selling bonds), the money supply falls and interest rates tend to rise. Higher interest rates increase demand for the domestic currency, so it tends to appreciate. Appreciation makes domestic goods more expensive to foreigners, which tends to lower net exports and shift aggregate demand left.

A related investment intuition that often appears in explanations: when interest rates rise, capital investment tends to decrease while financial investment (holding interest-bearing assets) becomes more attractive.

Fiscal policy impact on exchange rates

Fiscal policy affects exchange rates mainly by changing aggregate demand, income, and (often) interest rates.

  • With expansionary fiscal policy (higher government spending or lower taxes), aggregate demand rises, real GDP rises, and the price level rises in the short run. The rise in income tends to increase imports (more supply of domestic currency in FOREX), while higher interest rates (if they rise) tend to attract capital inflows (more demand for domestic currency). In many AP chains, the interest-rate/capital-inflow effect is emphasized as a source of appreciation pressure.

  • With contractionary fiscal policy (lower government spending or higher taxes), aggregate demand falls, real GDP falls, and the price level falls in the short run. Lower income tends to reduce imports, and lower interest rates (if they fall) reduce capital inflows; these forces typically reduce appreciation pressure and can contribute to depreciation.

Exam Focus
  • Typical question patterns
    • Given a scenario (higher domestic inflation, higher domestic interest rate, recession abroad, changed tastes, speculators shifting expectations), predict appreciation/depreciation.
    • Explain how expansionary vs contractionary monetary policy changes interest rates, currency demand, and exchange rates.
    • Use the “determinants list” (tastes, trade prices/relative price levels, income, real interest rates) to justify a shift in demand or supply.
  • Common mistakes
    • Ignoring speculation and treating exchange rates as driven only by trade.
    • Confusing the trade-based income effect (imports change supply) with the interest-rate effect (assets change demand).
    • Stating a direction (appreciate/depreciate) without identifying whether demand or supply shifted and why.

Currency Movements: Effects on Net Exports, Aggregate Demand, and Inflation

Exchange rates are central because they link international markets to domestic output and inflation.

How appreciation and depreciation affect net exports

Using the “foreign currency per domestic currency” framework:

  • If the domestic currency appreciates, domestic goods become more expensive to foreigners and foreign goods become cheaper to domestic buyers. Exports fall, imports rise, and NX falls.
  • If the domestic currency depreciates, domestic goods become cheaper to foreigners and foreign goods become more expensive domestically. Exports rise, imports fall, and NX rises.

Net exports and aggregate demand

Aggregate demand includes net exports:

AD = C + I + G + NX

So, when depreciation raises NX, aggregate demand tends to shift right; when appreciation lowers NX, aggregate demand tends to shift left.

Consequences of changes in net exports

Changes in net exports have predictable macro consequences:

  • If NX decreases: aggregate demand decreases; exports become more expensive; demand for domestic goods decreases; production and employment decrease; output decreases.
  • If NX increases: aggregate demand increases; exports become cheaper; demand for domestic goods increases; production and employment increase; output increases.

Example: depreciation and AD

If the domestic currency depreciates significantly, imports become more expensive and exports become cheaper to foreigners, so NX increases and aggregate demand shifts right. In the short run, real GDP rises and the price level tends to rise.

Exchange rates and inflation: imported inflation vs disinflation

Exchange rates affect inflation through import prices.

  • Depreciation can create imported inflation because imported consumer goods and imported inputs (like oil or components) become more expensive in domestic currency, pushing costs and the price level up.
  • Appreciation can reduce inflation pressure by making imports cheaper.

Example: interest rate increase, appreciation, and net exports

If the central bank raises interest rates, domestic assets attract foreign investors, demand for the domestic currency rises, and the currency appreciates. Exports fall and imports rise, so NX falls and aggregate demand decreases relative to what it otherwise would have been.

Exam Focus
  • Typical question patterns
    • Predict how appreciation/depreciation changes exports, imports, and NX.
    • Use an AD-AS graph to show how exchange-rate changes shift AD through NX.
    • Explain how exchange-rate movements affect inflation through import prices (especially with imported oil or imported inputs).
  • Common mistakes
    • Saying “appreciation increases exports” (it generally decreases exports).
    • Forgetting that interest rates affect exchange rates through asset flows, not just trade.
    • Treating a stronger currency as “always good” and ignoring the potential fall in NX and output in export industries.

International Capital Flows and Real Interest Rates

International capital flows are driven heavily by comparative returns on assets across countries and connect directly to exchange rates and net exports.

Inbound vs outbound capital flow

  • Inbound capital flow is the injection of funds into a domestic economy through the purchase of domestic assets by foreign investors. High real interest rates tend to generate inbound capital flow because foreign investors seek higher returns.
  • Outbound capital flow is the extraction of funds from a domestic economy through the purchase of foreign assets by domestic investors. When real interest rates fall (relative to abroad), funds tend to flow out toward higher-return opportunities elsewhere.

Impact of real interest rates on the currency and net exports

  • A higher real interest rate (relative to another country) tends to make the higher-interest-rate country’s currency appreciate. Appreciation makes exports more expensive and imports cheaper, tending to decrease NX.
  • A lower real interest rate tends to make the currency depreciate. Depreciation makes exports cheaper and imports more expensive, tending to increase NX.

Central banks, banks, and domestic interest rates

Central banks play a major role in determining domestic interest rates using tools such as open market operations, the discount rate, and reserve requirements.

Domestic interest rates affect net capital inflows because they change how attractive a country’s assets are to foreign investors (high domestic rates attract inflows; low domestic rates reduce inflows).

Banks also influence domestic interest rates. When banks raise rates charged on loans, borrowing costs rise for households and firms, contributing to higher economy-wide interest rates. When banks raise rates paid on deposits, saving becomes more attractive, which can reduce spending and also contribute to higher interest rates.

Exam Focus
  • Typical question patterns
    • Explain how a change in real interest rates causes inbound or outbound capital flow and shifts currency demand.
    • Connect interest-rate-driven appreciation/depreciation to changes in NX.
    • Identify the role of the central bank’s policy tools in shifting interest rates and therefore capital flows.
  • Common mistakes
    • Mixing up inbound vs outbound capital flows.
    • Jumping from “interest rates change” to “NX changes” without the exchange-rate step.
    • Treating capital flows as unrelated to the FX market (they are a major driver of currency demand).

Trade Policy: Tariffs, Quotas, and Subsidies

Trade policy tools change incentives to import and export and can also feed back into exchange rates.

Tariffs

A tariff is a tax on imported goods.

Two common tariff purposes:

  • Revenue tariff: a tax on goods not produced in the domestic market, mainly to raise revenue. Example: if the United States does not produce bananas, a tariff on bananas would not seriously impede trade but would raise some government revenue.
  • Protective tariff: a tax on a good produced domestically, intended to protect domestic producers from foreign competition.

Protective tariff example (steel): Assume the domestic steel price is 100 dollars per ton and the equilibrium quantity of domestic steel is 10 million tons. In the world market, the price is 80 dollars per ton. At 80 dollars, the United States would demand 12 million tons but produce only 8 million tons, so 4 million tons are imported. If a protective tariff raises the world price by 10 dollars to 90 dollars, the quantity of domestic steel supplied increases and steel imports fall from 4 million tons to 2 million tons.

Economic effects of the tariff

A tariff generally leads to:

  • Consumers paying higher prices and consuming less of the tariffed good.
  • Loss of consumer surplus and the creation of deadweight loss.
  • Domestic producers increasing output because they can sell more at the higher price.
  • Declining imports.
  • Tariff revenue collected by the government. In the steel example, revenue is 10 dollars per ton times 2 million imported tons, which equals 20 million dollars. This is a transfer from consumers to the government, not a net gain in total well-being.
  • Inefficiency because production shifts toward less efficient domestic producers and away from more efficient foreign producers, diverting resources from the efficient sector to the inefficient sector.

Quotas

An import quota limits the quantity of a good that can be imported.

If a quota allows only 2 million tons of steel to be imported, the impact (except for tariff revenue) is similar to a protective tariff: higher consumer prices, lower consumer surplus, inefficient resource allocation, and deadweight loss.

Tariffs vs quotas (key comparisons)

Tariffs and quotas share major effects:

  • Both hurt consumers with artificially high prices and lower consumer surplus.
  • Both protect inefficient domestic producers at the expense of efficient foreign firms, creating deadweight loss.
  • Both reallocate resources toward inefficient producers.

A key difference: tariffs collect revenue for the government; quotas do not (in the basic comparison).

Subsidies (briefly)

A subsidy is a government payment that lowers production costs for domestic firms. Subsidies can increase exports by making domestic goods cheaper for foreign buyers, but they cost government revenue and can create inefficiencies.

Exchange-rate feedback from import restrictions

If a tariff or quota reduces imports, domestic residents demand less foreign currency, which means fewer dollars are supplied in foreign exchange markets. Reduced supply of dollars can contribute to domestic currency appreciation. That appreciation makes exports harder to sell and imports cheaper, potentially offsetting some of the intended increase in NX.

Exam Focus
  • Typical question patterns
    • Identify effects of a tariff or quota on domestic price, domestic output, and imports.
    • Explain who gains and loses (domestic producers vs domestic consumers).
    • Compare tariffs vs quotas, including the government revenue difference.
    • Connect import restrictions to FX markets (less demand for foreign currency implies less supply of domestic currency).
  • Common mistakes
    • Claiming tariffs lower domestic prices (they generally raise prices).
    • Treating quotas and tariffs as identical (price-based tax vs quantity restriction).
    • Ignoring possible exchange-rate feedback that can offset intended changes in NX.

Exchange Rate Regimes and Central Bank Intervention

An exchange rate regime is how a country manages the value of its currency.

Floating exchange rates

Under a floating exchange rate system, currency values are determined largely by supply and demand in the foreign exchange market. Exchange rates can change quickly with interest rates and expectations, and depreciation can help boost exports during downturns.

Fixed (pegged) exchange rates

Under a fixed (pegged) system, a government or central bank commits to keeping the exchange rate at or near a target value.

If market forces push the exchange rate away from the peg, the central bank intervenes as a buyer or seller of last resort:

  • If the domestic currency faces pressure to depreciate (too much supply of domestic currency), the central bank buys domestic currency (reducing its supply), often using foreign currency reserves.
  • If the domestic currency faces pressure to appreciate (too much demand), the central bank sells domestic currency (increasing its supply) to prevent appreciation.

A key limitation is that defending a peg often requires substantial foreign exchange reserves and may force monetary policy to prioritize the exchange rate over domestic goals.

Devaluation vs depreciation

  • Depreciation is a market-driven fall in a currency’s value under floating rates.
  • Devaluation is an official policy-driven reduction in the pegged value of a currency.

Example: defending a peg (conceptual)

Suppose a country pegs its currency at 2 units of domestic currency per 1 dollar. If investors lose confidence and want to sell the domestic currency, the market would push the currency lower. To maintain the peg, the central bank must buy domestic currency and sell foreign reserves. If reserves run low, maintaining the peg becomes difficult.

Exam Focus
  • Typical question patterns
    • Distinguish depreciation vs devaluation in floating vs fixed regimes.
    • Explain what the central bank must do to maintain a peg under appreciation or depreciation pressure.
    • Predict how capital flight or interest rate changes create pressure on a fixed exchange rate.
  • Common mistakes
    • Using “devalue” for any fall in a currency under floating rates.
    • Forgetting intervention requires reserves.
    • Describing a peg as “no change ever” rather than an ongoing commitment that often requires continuous action.

Putting the Open Economy Together: Integrated Cause-and-Effect Chains

AP Macroeconomics often expects multi-step reasoning that links monetary policy, interest rates, capital flows, exchange rates, net exports, aggregate demand, and sometimes the balance of payments.

The “interest rate to exchange rate to net exports” chain

If domestic interest rates rise relative to the rest of the world:

  1. Domestic assets become more attractive.
  2. Financial capital flows in (foreigners buy more domestic assets).
  3. Demand for the domestic currency rises.
  4. The domestic currency appreciates.
  5. Exports fall and imports rise.
  6. NX falls.
  7. Aggregate demand shifts left relative to otherwise.

If domestic interest rates fall relative to the rest of the world:

  1. Financial capital flows out.
  2. Demand for domestic currency falls.
  3. The domestic currency depreciates.
  4. NX rises.
  5. Aggregate demand shifts right.

The “domestic income to imports to currency” chain

If domestic GDP rises (a boom):

  1. Consumers and firms buy more goods overall.
  2. Imports tend to rise.
  3. Supply of domestic currency in FX markets increases (to buy foreign currency).
  4. The domestic currency tends to depreciate.

Worked integrated example (typical AP reasoning)

Scenario: The central bank implements contractionary monetary policy.

A complete explanation:

  • Contractionary monetary policy raises interest rates.
  • Higher interest rates attract foreign investment into domestic bonds.
  • Foreign demand for the domestic currency rises, so the currency appreciates.
  • Appreciation reduces exports and increases imports, lowering NX.
  • Lower NX reduces aggregate demand.

This is a common AP twist: in an open economy, contractionary monetary policy can reduce aggregate demand not only through lower investment, but also through appreciation lowering net exports.

Balance of payments connection in an integrated story

If interest rates rise and foreign investors buy more domestic bonds, that purchase is recorded as a financial account inflow (a financial account surplus in the simplified sign logic). The increased demand for domestic currency contributes to appreciation, and appreciation tends to reduce NX, pushing the current account toward deficit (or shrinking a surplus). This ties together the “two sides of the same coin”: capital flows and trade flows are linked through the currency market.

Common graphing expectations in AP responses

AP prompts often expect you to combine:

  • a FOREX graph showing appreciation/depreciation via a shift in demand or supply,
  • a clear statement of what happens to exports/imports and NX,
  • an AD-AS graph showing AD shifting because NX changed,
  • and sometimes an interpretation of the current account and financial account.

The most reliable strategy is to explain the mechanism as a chain of cause and effect, justifying every step.

Exam Focus
  • Typical question patterns
    • Multi-step prompts linking monetary policy to interest rates, exchange rates, NX, and AD.
    • Questions that combine balance of payments with FX market shifts (for example, “a financial account surplus implies what about the current account?”).
    • Graph-based free-response parts that require consistent labels and directional changes.
  • Common mistakes
    • Skipping steps (for example, moving from interest rates to exports without the exchange-rate link).
    • Getting the direction wrong for NX after appreciation/depreciation.
    • Mixing up which balance of payments account records a transaction (goods/services and income vs assets), causing contradictions.