Macroeconomics Study Guide: International Linkages, Exchange Rates, and Policy in an Open Economy

Covid-19 and the Global Economy

Globalization and Economic Shocks

The Covid-19 pandemic highlighted the interconnectedness of the global economy. Uncertainty led to forecasting errors by firms, which were amplified by globalization.

• Globalization: The increasing integration of economies worldwide through trade, investment, and technology.

• Example: Vehicle computer chip manufacturers underestimated demand, leading to a global shortage and higher automobile prices in the U.S. in 2021.

International Linkages and the Balance of Payments

Trade and Financial Flows

Countries are linked through trade in goods/services and financial investments. Understanding these linkages is crucial for analyzing fiscal and monetary policy impacts.

• Trade: Exchange of goods and services across borders.

• Financial Investment: Cross-border flows of capital, such as investments in stocks, bonds, or physical assets.

Open vs. Closed Economies

An open economy interacts with other countries in trade or finance, while a closed economy does not. Today, nearly all economies are open to some degree.

• Open Economy: Engages in international trade and financial transactions.

• Closed Economy: No international trade or financial flows (rare; e.g., North Korea).

Balance of Payments (BoP)

The balance of payments is a record of a country's transactions with the rest of the world, including trade in goods/services and asset flows.

• Current Account: Records net exports, net income on investments, and net transfers.

• Financial Account: Records purchases of assets abroad and foreign purchases of domestic assets.

• Capital Account: Records minor transactions (e.g., migrants' transfers, sales of nonproduced assets).

U.S. Balance of Payments, 2020 (Billions of Dollars)

Account	Main Components	2020 Value (USD billions)
Current Account	Exports of goods/services, net income, net transfers	-971
Financial Account	Net asset purchases/sales	741
Capital Account	Minor transactions	-5

Additional info: The sum of all accounts is approximately zero, as required by accounting identity.

Trade Balance and Current Account

The trade balance is the difference between the value of exports and imports of goods. A positive balance is a surplus; a negative balance is a deficit.

• Current Account = Trade Balance + Balance of Services + Net Income on Investments + Net Transfers

• For the U.S., net exports are often used as a proxy for the current account balance.

Financial Account and Net Foreign Investment

The financial account tracks long-term flows of funds, including purchases of financial and physical assets.

• Capital Outflows: Purchases of foreign assets by domestic residents.

• Capital Inflows: Purchases of domestic assets by foreigners.

• Net Foreign Investment (NFI): Difference between capital outflows and inflows.

Formula:

$\text{Net Foreign Investment} = \text{Capital Outflows} - \text{Capital Inflows}$

Why Is the Balance of Payments Always Zero?

The sum of the current account, financial account, and capital account balances must be zero. This reflects the accounting identity: every international transaction is both a credit and a debit.

• If a country spends more on foreign goods/services than it receives, it must finance the difference by selling assets or borrowing.

Foreign Exchange Market and Exchange Rates

Nominal and Real Exchange Rates

The nominal exchange rate is the value of one currency in terms of another. The real exchange rate adjusts for price level differences between countries.

• Example: If $1 = ¥100$, then $1 can buy 100 Japanese yen.

• Formula (Real Exchange Rate):

$\text{Real Exchange Rate} = \frac{\text{Nominal Exchange Rate} \times \text{Foreign Price Level}}{\text{Domestic Price Level}}$

Equilibrium in the Foreign Exchange Market

Exchange rates are determined by supply and demand for currencies.

• Demand for $US: Foreigners wanting to buy U.S. goods/services, invest in U.S. assets, or currency traders expecting appreciation.

• Supply of $US: Americans wanting to buy foreign goods/services or invest abroad.

• Equilibrium Exchange Rate: Where quantity supplied equals quantity demanded.

Exchange Rate Determination Table

Factor	Effect on Exchange Rate
Increase in U.S. income	Supply of $US rises (more imports)
Increase in U.S. interest rates	Demand for $US rises (more attractive assets)
Expectations of appreciation	Demand for $US rises

Market vs. Fixed Exchange Rates

Most exchange rates are determined by the market, but some countries fix their currency's value (e.g., China fixed the yuan at 8.28 yuan = $1 for over a decade).

Shifts in Demand and Supply for Foreign Exchange

Factors other than the exchange rate itself can shift demand and supply curves:

• Changes in demand for domestic vs. foreign goods/services

• Changes in investment preferences

• Expectations about future exchange rates

Exchange Rates, Imports, and Exports

When the domestic currency appreciates:

• Imports become cheaper for domestic consumers.

• Exports become more expensive for foreign buyers.

• Example: If $US appreciates from $1=€1 to $1=€1.20, a $200 iPhone costs €240 instead of €200 for a French buyer, reducing demand for U.S. exports.

Case Study: Toyota and Exchange Rate Fluctuations

Toyota's profits are affected by exchange rate changes:

• Stronger yen: Yen is worth more per dollar; U.S. dollar exchanges for fewer yen.

• Reduces profits by making exports more expensive and reducing the value of dollar earnings when converted to yen.

• Producing cars in the U.S. reduces exposure to exchange rate risk.

Is a Strong Currency Good for a Country?

A strong currency makes imports cheaper and exports more expensive. The impact depends on the structure of the economy and the balance between imports and exports.

• Firms may benefit or suffer depending on whether they rely more on imported inputs or exported outputs.

National Saving, Investment, and the International Sector

Saving and Investment Relationships

When a country's spending exceeds its income, it must finance the difference by selling assets or borrowing. This relationship is captured by the following identity:

• Current Account Balance + Financial Account Balance = 0

• Net Export = Net Foreign Investment

Domestic Saving and Investment

National saving is the sum of private and public saving:

• Formula:

$S = S_{private} + S_{public}$

$S_{private} = Y + TR - C - T$

$S_{public} = T - G - TR$

$S = Y - C - G$

The Saving and Investment Equation

Relates national saving, investment, and net exports:

• National Income Identity:

$Y = C + I + G + NX$

• Saving and Investment Equation:

$S = Y - C - G = I + NX$

Since $NX = NFI$ (Net Foreign Investment):

$S = I + NFI$

• Interpretation: National saving finances both domestic investment and net foreign investment.

Government Budget Deficits and Investment

Budget deficits reduce national saving, which can lead to higher interest rates and currency appreciation, reducing net exports.

• Twin Deficits: Occur when budget deficits coincide with current account deficits.

• Higher interest rates attract foreign investment, causing the currency to appreciate and net exports to fall.

Policy in an Open Economy

Monetary Policy

Monetary policy is more effective in an open economy due to additional channels:

• Lower interest rates can lead to currency depreciation, boosting net exports and aggregate demand.

• Expansionary monetary policy increases aggregate demand more in an open economy than in a closed one.

Fiscal Policy

Fiscal policy is less effective in an open economy:

• Increased government spending may raise interest rates, causing currency appreciation and reducing net exports.

• The multiplier effect is smaller, as some spending leaks into imports.

Summary Table: Key Macroeconomic Relationships

Identity	Equation (LaTeX)	Interpretation
National Saving	$S = Y - C - G$	Income not consumed or spent by government
National Income	$Y = C + I + G + NX$	GDP equals sum of expenditures
Saving-Investment	$S = I + NX$	Saving finances investment and net exports
Net Exports	$NX = NFI$	Net exports equal net foreign investment

Examples and Applications

• Apple and iPhone Manufacturing: U.S. policies aim to reduce the current account deficit by encouraging domestic production, but practical challenges (supply chains, skilled labor) limit effectiveness.

• U.S. Budget Deficits: International capital flows can offset low domestic saving, but persistent patterns may be inefficient in the long run.

• Toyota: Exchange rate fluctuations affect profits, especially for firms exporting goods produced in their home country.

Additional info: These notes expand on the original slides by providing definitions, formulas, and context for key macroeconomic concepts relevant to open economies, international linkages, and policy effectiveness.