Comprehensive Guide to AP Macroeconomics Unit 6: International Trade and Finance

6.1 Balance of Payments Accounts

The Balance of Payments (BoP)

The Balance of Payments is a record of all international trade and financial transactions made by a country's residents (individuals, businesses, and government) with the rest of the world over a specific period. It measures the flow of money between a nation and foreign countries.

The BoP follows a fundamental identity:
Current\ Account\ (CA) + Financial\ Account\ (CFA) = 0
(Note: In some older textbooks, the Financial Account is called the Capital Account, but AP Macroeconomics primarily uses "Financial Account".)

1. The Current Account (CA)

The Current Account records trades in goods and services, investment income, and current transfers. It measures the flow of funds for "now" transactions. It consists of three specific components:

• Balance of Trade (Net Exports): The difference between the value of exports and imports of goods and services.
  • Trade Deficit: Imports > Exports (Money flowing out).
  • Trade Surplus: Exports > Imports (Money flowing in).
• Net Investment Income: Income earned on foreign assets (e.g., dividends a US citizen earns from a French company) minus income paid to foreign investors (e.g., interest paid to a Japanese holder of a US Treasury bond).
• Net Transfer Payments: Money sent without goods or services being exchanged (e.g., foreign aid, remittances sent by immigrants to families back home).

2. The Financial (Capital) Account (CFA)

The Financial Account records the purchase and sale of financial assets and real assets between a country and the rest of the world. It measures the flow of funds for "future" claims.

• Financial Assets: Stocks, corporate bonds, government securities (Treasury bills).
• Real Assets: Real estate, factories, office buildings (Foreign Direct Investment).

Rules of Movement:

• Capital Inflow (CFA Surplus): Foreigners buying domestic assets (money flows IN to the country).
  • Example: A Swedish company buys a factory in Ohio.
• Capital Outflow (CFA Deficit): Domestic citizens buying foreign assets (money flows OUT of the country).
  • Example: An American teacher buys stock in a South Korean tech company.

The Relationship Between CA and CFA

Because every transaction has two sides (you get a good, you pay money), the accounts must theoretically sum to zero.

• If a country has a Current Account Deficit (buying more goods than selling), it must pay for that excess consumption by selling assets (borrowing), leading to a Financial Account Surplus.
• If a country has a Current Account Surplus, it is accumulating foreign currency, which it uses to buy foreign assets, leading to a Financial Account Deficit.

Common Mistakes

• Mistake: Thinking borrowing money from a foreign bank is in the Current Account.
  • Correction: Loans and debt repayment principal are financial assets/liabilities. They go in the Financial Account. Only the interest payments go in the Current Account.
• Mistake: Confusing the term "Capital" in BoP with "Capital Goods" (machinery).
  • Correction: In BoP contexts, "Capital/Financial" refers to money flows for assets, not physical tractors or tools (unless the factory itself is bought).

6.2 Exchange Rates and the Foreign Exchange (FOREX) Market

Exchange Rate Definitions

An Exchange Rate is the price of one currency in terms of another currency. Currencies are bought and sold in the Foreign Exchange (FOREX) Market.

• Appreciation: When a currency gains value relative to another currency. (1 USD buys more Euros).
• Depreciation: When a currency loses value relative to another currency. (1 USD buys fewer Euros).

Graphing the FOREX Market

When graphing the market for specific currency (e.g., US Dollars):

1. X-Axis: Quantity of US Dollars.
2. Y-Axis: Price of the Dollar expressed in the other currency (e.g., "Euros per Dollar" or $\text{€}/\$$).

Demand for Currency

The demand for a currency (e.g., the US Dollar) comes from foreigners who need that currency to:

• Buy that country's exports (Tourists need Dollars to visit NYC).
• Invest in that country's financial assets (Japanese investors need Dollars to buy US Bonds).

Relationship: There is an inverse relationship. As the exchange rate rises (Dollar gets expensive), US goods become expensive to foreigners, so they demand fewer Dollars.

Supply of Currency

The supply of a currency comes from domestic citizens supplying their own currency to get foreign currency to:

• Buy imports.
• Invest abroad.

Relationship: There is a direct relationship. As the exchange rate rises (Dollar gets strong), foreign goods look cheap to Americans, so they supply more Dollars to buy those foreign goods.

6.3 Determinants of Exchange Rates (Shifters)

Changes in the FOREX market are driven by shifts in the Supply and Demand curves. We can use the mnemonic T.R.I.P.S. to remember the shifters.

1. Tastes and Preferences

If consumers prefer foreign goods, demand for that foreign currency increases, and supply of domestic currency increases.

• Example: If British citizens suddenly love American music, demand for USD increases $\rightarrow$ USD Appreciates.

2. Real Interest Rates (Crucial for AP Exams)

Money flows to the country with the highest real interest rate because investors seek the highest return on savings/bonds.

• Rule: If US Real Interest Rates $\uparrow$ $\rightarrow$ Foreigners demand US bonds $\rightarrow$ Demand for USD $\uparrow$ $\rightarrow$ USD Appreciates.
• Simultaneously, Americans keep money at home (Supply of USD $\downarrow$).

3. Income Levels (Relative Income)

When a nation's income (GDP) rises, its citizens have more disposable income to buy goods, including imports.

• Rule: If US Income $\uparrow$ $\rightarrow$ Americans buy more imports $\rightarrow$ Supply of USD increases on FOREX $\rightarrow$ USD Depreciates.
• Note: This is often counterintuitive. A booming economy often creates a depreciating currency initially due to the import effect, unless offset by interest rates.

4. Price Levels (Inflation)

If a country has high inflation, its goods are expensive compared to other nations.

• Rule: If US Inflation > Japan Inflation $\rightarrow$ US goods are unattractive $\rightarrow$ Demand for USD $\downarrow$. Simultaneously, Japanese goods are relatively cheap $\rightarrow$ Supply of USD $\uparrow$ (to buy Yen). Result: USD Depreciates.

5. Speculation

If investors predict a currency will rise in value in the future, they buy it now.

Summary Table of Shifters

6.4 Effect of Policy on Foreign Exchange

Fiscal and Monetary policies impact the exchange rate primarily through Income and Interest Rate channels.

Fiscal Policy Impact

Scenario: Expansionary Fiscal Policy (Gov Spending $\uparrow$ or Taxes $\downarrow$).

1. Interest Rate Effect (Dominant Short-Run Effect):
   • Gov borrows money (Deficit Spending) $\rightarrow$ Demand for Loanable Funds $\uparrow$ $\rightarrow$ Real Interest Rate $\uparrow$.
   • High Interest Rates attract foreign capital $\rightarrow$ Demand for Currency $\uparrow$ $\rightarrow$ Appreciation.
2. Price Level/Income Effect:
   • AD $\uparrow$ $\rightarrow$ Price Level $\uparrow$ and GDP $\uparrow$ $\rightarrow$ Imports $\uparrow$ $\rightarrow$ Depreciation.

AP Exam Tip: In almost all AP Macro questions regarding Fiscal Policy and exchange rates, the Interest Rate effect is the primary driver. Therefore, Expansionary Fiscal Policy $\rightarrow$ Higher Interest Rates $\rightarrow$ Appreciation.

Monetary Policy Impact

Scenario: Expansionary Monetary Policy (Fed buys bonds).

1. Money Supply $\uparrow$ $\rightarrow$ Interest Rates $\downarrow$.
2. Low interest rates make domestic financial assets less attractive.
3. Financial Capital flows OUT to other countries.
4. Demand for Domestic Currency $\downarrow$, Supply of Domestic Currency $\uparrow$.
5. Result: Currency Depreciates.

Trade Barriers (Tariffs and Quotas)

While primarily microeconomic tools, trade barriers affect the FOREX market by altering demand for imports.

• Protective Tariff: A tax on imported goods.
  • Tariffs make imports expensive $\rightarrow$ Domestic citizens decrease Net Imports $\rightarrow$ Supply of domestic currency on FOREX $\downarrow$ $\rightarrow$ Domestic Currency Appreciates.
• Note on Efficiency: Tariffs create deadweight loss, reduce consumer surplus, and artificially prop up inefficient domestic industries.

6.5 Changes in FOREX and Net Exports

The exchange rate acts as a feedback loop for the aggregate economy.

Logic Chain: Appreciation

1. Currency Appreciates (stronger dollar).
2. Foreigners find US goods more expensive $\rightarrow$ Exports $\downarrow$.
3. Americans find foreign goods cheaper $\rightarrow$ Imports $\uparrow$.
4. Net Exports (X - M) Decrease.
5. Since $AD = C + I + G + Xn$, Aggregate Demand shifts Left.

Logic Chain: Depreciation

1. Currency Depreciates (weaker dollar).
2. Foreigners find US goods cheaper $\rightarrow$ Exports $\uparrow$.
3. Americans find foreign goods expensive $\rightarrow$ Imports $\downarrow$.
4. Net Exports (X - M) Increase.
5. Aggregate Demand shifts Right.

Example Scenario

If the US is in a recession, the Fed might enact expansionary monetary policy.

• MS $\uparrow$ $\rightarrow$ Interest Rates $\downarrow$ $\rightarrow$ Dollar Depreciates $\rightarrow$ Net Exports $\uparrow$.
• This increase in Net Exports reinforces the expansionary policy, helping move the economy back to full employment.

6.6 Real Interest Rates and International Capital Flows

This section bridges the Loanable Funds Market (Unit 4) and the Foreign Exchange Market (Unit 6). This is a frequent synthesis question on Free Response Questions (FRQs).

The Mechanism

Capital flows seek the highest rate of return adjusted for risk.

Scenario: Country A has a Higher Real Interest Rate than Country B

1. Investors: Investors in Country B see high rates in Country A.
2. Flow: They take their money out of Country B (Capital Outflow) and send it to Country A (Capital Inflow).
3. FOREX Impact: To buy assets in Country A, they must buy Country A's currency.
   • Demand for Currency A $\uparrow$.
   • Supply of Currency B $\uparrow$.
4. Result: Currency A Appreciates; Currency B Depreciates.

Comparing Loanable Funds and FOREX

Common Mistakes in Unit 6

1. Confusing nominal and real interest rates: While nominal rates matter, international investors care about real interest rates (Nominal - Inflation) because that represents true purchasing power gain.
2. Mixing up Price Level and Exchange Rate effects:
   • High Price Level (Inflation) $\rightarrow$ Depreciates currency (nobody wants expensive goods).
   • High Exchange Rate (Appreciation) $\rightarrow$ Lowers Price Level (via cheaper imports and reduced AD).
3. The "Strong" Currency Fallacy: Students often assume a "strong" (appreciated) dollar is always "good." It is good for consumers (cheap imports/travel) but bad for producers (exporters hurt). A "weak" dollar is good for exporters but bad for consumers.