Global Economics¶

Why This Matters¶

Global Economics is the course that explains the world your business operates in. While other courses teach you to optimize a company from the inside -- pricing products, managing operations, financing investments -- this course teaches you to read the external environment: Why are prices rising? Why did the currency just collapse? Why is the central bank raising rates, and what does that mean for your cost of capital, your export revenues, and your hiring plans?

The course moves from the micro to the macro to the global. It starts with supply and demand in individual markets (microeconomics), then zooms out to the economy as a whole (macroeconomics), and finally opens the borders to examine how trade, capital flows, and exchange rates connect national economies. At every stage, the question is the same: What changed, and what happens next?

What makes this course distinctive is that it is deeply practical. You are not just learning theory -- you are learning to do back-of-the-napkin reasoning. If interest rates rise 1%, what happens to the exchange rate? To GDP? To investment? If the government increases spending, does it crowd out private investment or stimulate growth? The answers depend on the structure of the economy (open vs. closed, fixed vs. flexible exchange rate), and this course gives you the frameworks to figure it out. The country cases in Module IV are where all the theory converges: you diagnose real economies using the full toolkit.

How It All Connects¶

The four modules build from the smallest unit of analysis to the largest.

Module I (Microeconomics, Sessions 1-4) teaches the foundational language of economics: supply and demand, equilibrium, elasticity, and the effects of government interventions (price controls and taxes). These tools apply to any specific market -- labor, housing, commodities, your product -- and they introduce the concept of efficiency and deadweight loss that recurs throughout the course.

Module II (Macroeconomics -- Closed Economy, Sessions 5-8) zooms out to the whole economy. You learn to measure economic activity (GDP, inflation, unemployment) and to analyze business cycles using the Aggregate Demand / Aggregate Supply (AD/AS) framework. You then learn how two policy levers -- monetary policy (central banks setting interest rates) and fiscal policy (government spending and taxation) -- can shift aggregate demand to stabilize the economy.

Module III (International Finance, Sessions 9-12) opens the borders. You learn how exchange rates are determined, how capital flows across countries, and how the balance of payments works. The critical insight is the impossible trinity: a country cannot simultaneously maintain a fixed exchange rate, free capital mobility, and independent monetary policy -- it must sacrifice one. This module also shows how fiscal and monetary policy effectiveness changes dramatically depending on the exchange rate regime.

Module IV (Country Cases, Sessions 13-21) applies everything. You diagnose real economies -- Hong Kong, Sri Lanka, the USA, Japan, Mexico, Chile, the Eurozone, and surprise cases -- using the full micro-macro-international toolkit. Each case forces you to identify the shock, trace it through the relevant framework, and evaluate the policy response.

The throughline: microeconomics gives you the building blocks (supply, demand, elasticity, efficiency); macroeconomics assembles them into an economy-wide framework (AD/AS); and international finance shows how those frameworks interact across borders.

Lesson 1: Competitive Markets I -- Supply, Demand, and Equilibrium¶

Session 1. Reading: Competitive Markets.

The Big Idea¶

Microeconomics studies how the interactions between buyers and sellers in specific markets determine prices and quantities. The supply-and-demand framework is the single most important tool in economics. It allows you to predict how any change in economic conditions -- a new regulation, a shift in consumer preferences, a rise in input costs -- will affect market prices and quantities. For managers, these forces shape revenues, costs, and strategic choices every day.

The Demand Curve¶

The demand curve shows how many units buyers are willing and able to purchase at each price. It slopes downward: as price rises, quantity demanded falls.

Shifts vs. Movements: - A change in the good's own price causes a movement along the demand curve. - A change in anything else (income, price of substitutes or complements, number of buyers, tastes, expectations) causes a shift of the demand curve.

The Supply Curve¶

The supply curve shows how many units sellers are willing and able to sell at each price. It slopes upward: as price rises, quantity supplied rises.

Shifts vs. Movements: - A change in the good's own price causes a movement along the supply curve. - A change in anything else (input prices, technology, number of sellers, expectations) causes a shift of the supply curve.

Market Equilibrium¶

The competitive equilibrium occurs where quantity demanded equals quantity supplied. At the equilibrium price p and quantity q, the market clears.

• If price > p*: excess supply (surplus) --> competition among sellers pushes price down.
• If price < p*: excess demand (shortage) --> competition among buyers pushes price up.

Consumer and Producer Surplus¶

Consumer Surplus (CS) = the area below the demand curve and above the equilibrium price. It measures how much buyers gain from participating in the market (the difference between willingness to pay and the price actually paid).

Producer Surplus (PS) = the area above the supply curve and below the equilibrium price. It measures how much sellers gain (the difference between the price received and their minimum willingness to sell).

Total Surplus = CS + PS = Total Gains from Trade

Competitive markets maximize total surplus -- this is the "invisible hand" of Adam Smith. The first question to ask when government regulation prevents the market from clearing: What is the externality or market failure that justifies the intervention?

Analyzing Economic Shocks: The Three-Step Method¶

When an event hits a market, follow these three steps:

1. Identify whether it shifts demand, supply, or both.
2. Direction: does the curve shift right (increase) or left (decrease)?
3. Compare the old and new equilibrium to determine the effect on price and quantity.

Key Insight -- Distinguishing Demand from Supply Shocks:

Observing price alone is not enough to diagnose what happened. A price increase could reflect either a positive demand shock or a negative supply shock -- but the quantity moves in opposite directions. This distinction is essential for correct diagnosis and prediction.

Price Elasticity of Demand¶

The price elasticity of demand measures the percentage change in quantity demanded when the good's own price decreases by 1%.

Eᵈ = % change in Qᵈ / % change in P

A more elastic demand curve is flatter; a more inelastic one is steeper.

Determinants of demand elasticity: - Availability of close substitutes -- more substitutes = more elastic. - Time horizon -- demand is more elastic over longer periods (consumers adjust). - Broad vs. narrow categories -- demand for "soft drinks" is more inelastic than demand for "Diet Coke" (substitution within category is possible for the narrow product).

Price Elasticity of Supply¶

The price elasticity of supply measures the percentage change in quantity supplied when the good's own price increases by 1%.

Eˢ = % change in Qˢ / % change in P

Determinants of supply elasticity: - Technology and capacity constraints -- easier to scale up = more elastic. - Time horizon -- supply is more elastic in the long run (firms expand capacity). - Entry and exit barriers -- easier entry = more elastic.

Why Elasticities Matter¶

Elasticities determine whether a shock translates primarily into price changes or quantity changes:

• Inelastic supply + demand shock --> mostly price adjustment, little quantity change (e.g., oil markets in the short run).
• Elastic supply + demand shock --> mostly quantity adjustment, little price change.
• Inelastic demand + supply shock --> large price change, small quantity change (e.g., gasoline after a refinery shutdown).
• Elastic demand + supply shock --> large quantity change, small price change.

Back-of-the-napkin: When analyzing any market shock, your first question should be: "How elastic are supply and demand?" The answer tells you whether to expect price volatility or quantity volatility.

Cross-reference: Elasticity concepts connect directly to Competitive Strategy (price sensitivity in Five Forces analysis), Marketing Management (pricing and demand curves), and Operations Strategy (capacity constraints determine supply elasticity).

Lesson 2: Competitive Markets II -- Applications¶

Session 2. Case: Automation and Job Polarization.

The Big Idea¶

This session applies the supply-and-demand framework to real-world labor markets. The case on automation and job polarization illustrates how technology acts as a supply or demand shock in specific labor markets -- increasing demand for high-skill and low-skill workers while reducing demand for middle-skill routine jobs. The framework from Lesson 1 predicts the resulting wage and employment effects.

Applying the Framework to Labor Markets¶

In labor markets, the "price" is the wage and the "quantity" is employment. Firms demand labor; workers supply it.

• Automation as a negative demand shock for routine jobs: Demand for middle-skill workers shifts left --> wages fall and employment drops.
• Automation as a positive demand shock for high-skill jobs: Demand for workers who complement technology shifts right --> wages and employment rise.
• The elasticity of labor supply determines whether the adjustment is primarily in wages or in employment levels.

Cross-reference: These labor market dynamics connect to Operations Strategy (automation decisions), Leadership (managing workforce transitions), and Competitive Strategy (how technology reshapes industry structure).

Lesson 3: Price Ceilings and Price Floors¶

Session 3. Reading: Price Ceilings and Floors. Case: Hurricane Sandy.

The Big Idea¶

When the government prevents prices from reaching equilibrium, it creates predictable inefficiencies. Price ceilings (maximum prices) create shortages; price floors (minimum prices) create surpluses. Both reduce total gains from trade. Understanding these effects is essential for evaluating real-world policies like rent control, minimum wages, and anti-gouging laws.

Price Ceilings¶

A price ceiling is a legal maximum price. It only matters (is "binding") when set below the equilibrium price.

Effects of a binding price ceiling: - Price falls to the ceiling level. - Quantity traded falls (determined by the lower quantity supplied at the ceiling price). - A shortage emerges: Qᵈ > Qˢ at the ceiling price.

Rationing mechanisms that replace price rationing: - Waiting in lines (costly and wasteful -- the cost to buyers yields no benefit to sellers). - Seller preferences (selling to friends, family, or favored groups -- inefficient and potentially discriminatory). - Black markets and side payments.

Four inefficiencies of binding price ceilings: 1. Wasted resources -- queuing and searching impose real costs with no offsetting benefit. 2. Inefficient allocation -- goods do not go to the buyers who value them most. 3. Missed gains from trade -- mutually beneficial transactions fail to occur. 4. Quality degradation -- sellers unable to charge higher prices may cut quality.

Example -- Rent Control: Barcelona's rent control law (a price ceiling on long-term apartment rentals) reduces the supply of rental housing, lowers quality, and forces tenants into costly searches -- exactly as the theory predicts.

Price Floors¶

A price floor is a legal minimum price. It only matters (is "binding") when set above the equilibrium price.

Effects of a binding price floor: - Price rises to the floor level. - Quantity traded falls (determined by the lower quantity demanded at the floor price). - An excess supply (surplus) emerges: Qˢ > Qᵈ at the floor price.

Example -- Minimum Wage: A sufficiently high minimum wage creates an excess supply of labor (unemployment). Workers willing to work for less than the minimum wage cannot find jobs. Firms willing to hire at lower wages cannot legally do so. The result: missed gains from trade in the labor market, and in some cases, the emergence of informal (illegal) labor markets.

General Principles¶

The key question for any price control: Even if the policy is well-intentioned, does the benefit to the protected group outweigh (a) the deadweight loss, (b) the harm to those excluded from the market, and (c) the unintended consequences (black markets, quality degradation, informal markets)?

Cross-reference: Price floors in labor markets connect to Leadership (compensation, workforce management). Anti-gouging laws (price ceilings during emergencies) are discussed in Analysis of Business Problems as ethical dilemmas.

Lesson 4: Taxes¶

Session 4. Reading: Taxes.

The Big Idea¶

Taxes create a wedge between the price buyers pay and the price sellers receive. Three critical insights: (1) who physically pays the tax is irrelevant for who actually bears the burden -- what matters is the relative elasticity of demand and supply; (2) taxes always impose costs on buyers and sellers that exceed the revenue the government collects; and (3) the excess cost (deadweight loss) is larger when demand and supply are more elastic.

Tax Incidence: Who Really Pays?¶

When a per-unit tax t is imposed, it drives a wedge between the buyer's price and the seller's price:

Price buyers pay - Price sellers receive = t

The tax burden falls more heavily on the more inelastic side of the market -- the side that cannot easily adjust its behavior.

The Intuition: If you cannot easily walk away from the market (inelastic), you will absorb most of the tax. If you can easily switch to substitutes or exit (elastic), the other side absorbs it.

Graphical Method -- The Tax Wedge: To analyze a per-unit tax t on a supply-and-demand diagram, wedge a vertical line of length t between the demand and supply curves, to the left of their original intersection. The top of the wedge is the price buyers pay; the bottom is the price sellers receive. The horizontal position gives the after-tax quantity.

Tax Revenue and Deadweight Loss¶

Tax Revenue (TR) = t x Q_after-tax (the green rectangle in the diagram -- the tax rate times the quantity that is still traded).

Deadweight Loss (DL) = the triangle of lost gains from trade -- transactions that would have occurred without the tax but no longer occur because the tax makes them unprofitable.

DL = Total Surplus without tax - (Total Surplus with tax + Tax Revenue)

Key relationships: - When demand and supply are inelastic: the tax reduces quantity only slightly --> high tax revenue, low deadweight loss. This is why governments tax goods with inelastic demand (cigarettes, gasoline) -- they raise revenue efficiently. - When demand and supply are elastic: the tax reduces quantity significantly --> low tax revenue, high deadweight loss. Taxing goods with elastic demand is inefficient because people simply stop buying. - Doubling the tax rate more than doubles the deadweight loss (DL grows with the square of the tax rate) but does not double the revenue. This is the economic logic behind the Laffer Curve.

Back-of-the-napkin: When evaluating any tax proposal, ask two questions: (1) How elastic are demand and supply? (This tells you the deadweight loss.) (2) Which side is more inelastic? (This tells you who actually pays.)

Cross-reference: Tax incidence connects to Corporate Finance (corporate tax affects cost of capital and investment decisions), Competitive Strategy (industry-specific taxes alter competitive dynamics), and Financial Accounting (tax accounting).

Lesson 5: Macroeconomic Equilibrium I -- GDP, Inflation, and the AD/AS Framework¶

Sessions 5-6. Readings: Introduction to Macroeconomics, Macroeconomic Equilibrium. Case: US Economy 2025.

The Big Idea¶

Macroeconomics studies economy-wide outcomes: total output, unemployment, inflation, and interest rates. For business leaders, these aggregates shape the environment in which all firm-level decisions are made. The AD/AS (Aggregate Demand / Aggregate Supply) framework is the macroeconomic equivalent of supply and demand -- it explains booms, recessions, and the adjustment mechanisms that pull the economy back toward equilibrium.

Measuring Economic Activity¶

Gross Domestic Product (GDP)¶

GDP (Gross Domestic Product) measures the market value of all final goods and services produced in an economy over a given period.

Nominal GDP vs. Real GDP:

Nominal GDP = P × Y (current prices x current quantities)

Real GDP = P_base × Y (base-year prices x current quantities)

Real GDP Growth = (Y₂₀₂₅ - Y₂₀₂₄) / Y₂₀₂₄

Because real GDP holds prices constant, it isolates changes in actual production. Real GDP growth is the better indicator for assessing whether the economy is expanding or contracting.

GDP by Expenditure (the demand-side identity):

Y = C + I + G + NX

Caveats: Real GDP does not fully capture the value of new goods, quality improvements, digital goods, household production, or the underground economy.

Inflation¶

Inflation (pi) measures the rate at which the general price level changes over time.

pi = (P₂₀₂₅ - P₂₀₂₄) / P₂₀₂₄

Inflation is measured by fixing quantities in a base year and tracking how prices change. Low and stable inflation supports planning and long-term investment. High or volatile inflation increases uncertainty and complicates decision-making.

Caveats: Measured inflation has difficulty capturing new goods, quality improvements, and changes in consumption patterns (substitution bias).

Unemployment¶

Unemployment Rate = Number of Unemployed / Labor Force

A person is unemployed if they do not have a job and are actively looking for one. The unemployment rate excludes discouraged workers who have stopped searching.

Interest Rates: Nominal vs. Real¶

The Fisher Equation:

rᵉ = i - piᵉ (expected real rate = nominal rate - expected inflation)

r = i - pi (realized real rate = nominal rate - actual inflation)

The Intuition: If you borrow at 5% nominal but inflation turns out to be 3%, your real cost of borrowing was only 2%. The real interest rate is what matters for economic decisions -- it captures the true cost of moving purchasing power across time.

Cross-reference: The Fisher Equation connects directly to Corporate Finance (real vs. nominal discount rates, cost of capital calculations) and Financial Accounting (inflation adjustments to financial statements).

Nominal vs. Real Variables -- The Fundamental Dichotomy¶

Nominal variables are measured in monetary units (dollars, euros). Real variables adjust for prices and reflect purchasing power. While nominal variables are more commonly quoted, real variables are the ones that matter for economic decision-making because they describe what agents can actually buy, produce, or consume.

Examples: nominal wage vs. real wage; nominal GDP vs. real GDP; nominal interest rate vs. real interest rate; nominal exchange rate vs. real exchange rate.

The AD/AS Framework¶

This is the macroeconomic equivalent of micro supply and demand. The axes are the aggregate price level (P) on the vertical axis and Real GDP (Y) on the horizontal axis.

Aggregate Demand (AD)¶

AD shows the relationship between the price level and the total quantity of final goods and services demanded. It slopes downward due to the wealth effect: as prices rise, the purchasing power of consumers declines, reducing consumption.

AD Shifters (anything that changes total spending at a given price level): - Changes in household wealth or expectations - Changes in business confidence - Expansionary or contractionary monetary policy - Expansionary or contractionary fiscal policy

Short-Run Aggregate Supply (SRAS)¶

SRAS shows the relationship between the price level and total output in the short run. It slopes upward because wages are "sticky" -- they do not adjust immediately to price changes. When output prices rise but wages lag behind, firms find it profitable to expand production.

SRAS Shifters: - Changes in nominal wages - Changes in inflation expectations - Supply-chain disruptions or improvements - Changes in prices of imported inputs (in open economies)

Long-Run Aggregate Supply (LRAS)¶

LRAS is a vertical line at potential output (Y*) -- the maximum sustainable level of production without generating wage or price pressures. In the long run, wages fully adjust to price changes, so the price level does not affect output.

LRAS Shifters (structural factors that change productive capacity): - Technological progress - Investments in human capital (education, training) - Changes in labor force participation - Institutional quality (property rights, rule of law) - Demographics

Dynamic Macroeconomic Adjustment¶

Long-run equilibrium: AD, SRAS, and LRAS all intersect at the same point. Output equals potential, and there is no pressure on wages or prices.

Short-run equilibrium: AD and SRAS intersect. Output may be above or below potential.

The Boom-Recession Cycle¶

Boom (Y > Y*): 1. Output exceeds potential --> labor markets tighten. 2. Wages rise --> production costs increase --> SRAS shifts left. 3. Price level rises (inflation temporarily increases). 4. Higher prices reduce quantity demanded (movement along AD). 5. Economy returns to potential output. Inflation returns to its stable rate.

Recession (Y < Y*): 1. Output falls below potential --> unemployment rises. 2. Wages fall (slowly) --> production costs decrease --> SRAS shifts right. 3. Price level falls (or inflation temporarily decreases). 4. Lower prices increase quantity demanded (movement along AD). 5. Economy returns to potential output. Inflation returns to its stable rate.

The Key Insight: The economy is self-correcting in the long run through wage adjustment, but the process can be slow and painful -- which is why governments use monetary and fiscal policy to speed up the return to potential.

Back-of-the-napkin: When diagnosing an economy, first ask: "Is output above or below potential?" If above, expect rising wages, rising inflation, and eventual slowdown. If below, expect slack labor markets, falling inflation, and eventual recovery -- unless policy intervenes.

Lesson 6: Interest Rates and Monetary Policy¶

Sessions 7. Reading: Monetary Policy and Inflation. Case: Federal Reserve.

The Big Idea¶

Central banks control short-term interest rates to keep inflation stable and to smooth business cycle fluctuations. The key concept is the neutral rate (r): the real interest rate at which monetary policy neither stimulates nor restrains aggregate demand. Policy is expansionary when the real policy rate is below r, and contractionary when above r*. A credible central bank anchors inflation expectations, giving it greater freedom to stabilize the economy.

Monetary Policy Mechanics¶

Central banks set a short-term nominal policy rate (i_policy) by adjusting the money supply. But what matters for the economy is the expected real policy rate:

rᵉ_policy = i_policy - piᵉ

Policy Stance:

The Neutral Rate (r*)¶

The neutral rate is NOT chosen by the central bank. It is determined by underlying economic forces in the financial (bond) market:

• Supply of funds = household saving decisions (upward sloping in r).
• Demand for funds = firm investment decisions + government borrowing (downward sloping in r).
• r* is the rate where desired saving = desired borrowing.

Factors that shift r*: - Investment opportunities (tech booms raise r). - Demographics and saving behavior (aging populations with high savings lower r). - Government borrowing (higher deficits raise demand for funds, pushing r* up).

Empirical proxies for r*: - Long-term government bond yield minus expected inflation (e.g., 10-year Treasury at 4.5% - 2% inflation target = r* of ~2.5%). - Central bank communications about long-run policy rate expectations.

Monetary Policy and Inflation Stability¶

Central banks announce and commit to an explicit inflation target. Credible commitment to this target anchors inflation expectations, which is essential for stable inflation.

Why credibility matters: - If the central bank is credible, firms and workers set wages and prices assuming inflation will stay near the target. - If credibility is weak, any temporary inflation spike gets built into expectations, making inflation self-reinforcing.

Response to demand shocks: After a negative demand shock (recession), the central bank can lower rates below r* to shift AD right. This stabilizes both output and inflation -- the two goals are aligned.

Response to supply shocks: After a negative supply shock (higher costs, lower output), the central bank faces a trade-off. Lowering rates to support output causes inflation to overshoot the target. Whether this is sustainable depends on credibility: a credible central bank can accommodate temporarily because firms and workers treat the overshoot as a one-time event. An incredible central bank risks a wage-price spiral.

The Transmission of Monetary Policy¶

The central bank controls the overnight interbank rate. The effectiveness of monetary policy depends on how well changes in this rate propagate to broader financial conditions (mortgage rates, corporate bond yields, bank lending rates):

• Strong transmission: small policy changes --> large shifts in AD.
• Weak transmission: even large rate changes have limited effect on broader rates and AD.

Unconventional Monetary Policy -- Quantitative Easing (QE): When short-term rates hit zero (the "zero lower bound" or ZLB (Zero Lower Bound)), conventional rate cuts are no longer possible. Central banks can then purchase long-term assets (government bonds, mortgage-backed securities) to push down long-term rates directly. QE works by increasing the money supply and compressing term premiums.

Back-of-the-napkin: "If interest rates rise 1%..." --> Investment falls (higher cost of capital) --> AD shifts left --> GDP growth slows --> Unemployment rises slightly --> If the rate hike was appropriate (inflation was above target), inflation moderates.

Cross-reference: The neutral rate concept connects directly to Corporate Finance (the risk-free rate in WACC calculations is a nominal interest rate that embeds both r and expected inflation). When r shifts, the cost of capital for every company shifts with it.

Lesson 7: Government and Fiscal Policy¶

Session 8. Reading: The Government and Fiscal Policy. Case: France.

The Big Idea¶

Governments influence the economy through spending, taxation, and transfers. Fiscal policy can stabilize business cycles by shifting aggregate demand, but it is constrained by the government's budget: persistent deficits accumulate debt, which raises borrowing costs and limits future policy flexibility. The interplay between fiscal and monetary policy is critical -- the two can reinforce or undermine each other.

Roles of Government in the Economy¶

1. Establishing a legal and social framework (property rights, contracts).
2. Maintaining competition (antitrust enforcement).
3. Providing public goods (roads, defense, infrastructure).
4. Redistributing income (progressive taxation, social safety nets).
5. Correcting externalities (pollution regulation, carbon taxes).
6. Stabilizing the economy through fiscal policy.

Government Policies and Long-Run Growth (LRAS Shifters)¶

Strong consensus: - Rule of law and property rights. - Infrastructure investment. - Smart regulation. - Human capital (education, workforce training).

Debated: - Industrial policy and innovation support. - Optimal tax rates (lower taxes to incentivize work/investment vs. higher taxes to fund productive public investment). - Income redistribution (social harmony vs. incentive distortion).

The Government Budget Constraint¶

G + Tr + iB_{t-1} = T + Delta_B

Primary Deficit = G + Tr - T (spending + transfers minus tax revenue, excluding interest on debt)

Overall Deficit = G + Tr - T + iB_{t-1} (including interest payments)

If the overall deficit is positive, the government must borrow --> debt stock grows --> interest payments grow --> fiscal flexibility shrinks. This is the debt spiral risk.

Fiscal Policy and Business Cycle Stabilization¶

Expansionary fiscal policy = any policy that increases the primary deficit (raise G, raise Tr, or cut T). This shifts AD right.

Contractionary fiscal policy = any policy that decreases the primary deficit (cut G, cut Tr, or raise T). This shifts AD left.

Critical nuance: If the government increases spending AND raises taxes by the same amount (balanced budget), the primary deficit is unchanged, and the net effect on AD is approximately zero. The primary deficit -- not individual components -- is what matters for the AD shift.

Fiscal vs. Monetary Policy: Key Differences¶

Crowding Out: Expansionary fiscal policy raises government borrowing, which increases demand for funds in financial markets, pushing interest rates (including the neutral rate r*) higher. This makes borrowing more expensive for private businesses and households, partially offsetting the stimulus. The degree of crowding out depends on how much rates rise and how sensitive private investment is to rates.

When fiscal policy is most important: When interest rates are at or near the zero lower bound and monetary policy has limited room to maneuver, fiscal policy becomes the primary tool for stabilization.

Cross-reference: Government borrowing and interest rates connect to Corporate Finance (cost of debt, WACC). Fiscal policy also connects to Competitive Strategy (government subsidies, industry policy) and Operations Strategy (infrastructure investment).

Lesson 8: Nominal and Real Exchange Rates¶

Session 9. Reading: Nominal and Real Exchange Rates. Mini case: Chilean Peso.

The Big Idea¶

Exchange rates are the prices that connect national economies. The nominal exchange rate is the price of one currency in terms of another; the real exchange rate adjusts for inflation differentials and determines the true competitiveness of a country's goods. Exchange rates are driven by both trade flows (exports and imports) and capital flows (cross-border investment), with capital flows often dominating in the short run.

The Nominal Exchange Rate¶

Convention used in this course:

E = units of domestic currency per unit of foreign currency

• E rises --> domestic currency depreciates (more domestic currency needed per unit of foreign).
• E falls --> domestic currency appreciates (less domestic currency needed per unit of foreign).

Warning: Always verify which currency is in the numerator. The same pair can be quoted either way in different markets.

Market Participants in the FX (Foreign Exchange) Market¶

Group A -- Real Economy (Trade in Goods and Services): - Exporters supply foreign currency (sell foreign currency earned from exports to buy domestic currency). A weaker domestic currency (higher E) improves their competitiveness. - Importers demand foreign currency (buy foreign currency to pay foreign suppliers). A stronger domestic currency (lower E) makes imports cheaper.

Group B -- Financial Economy (Capital Flows): - Investors buying domestic assets supply foreign currency (sell foreign currency to buy domestic currency for asset purchases). Attracted by higher domestic risk-adjusted returns. - Investors buying foreign assets demand foreign currency. Attracted by higher foreign risk-adjusted returns.

Capital inflow = net flow of investment into the domestic economy (investors selling foreign assets, buying domestic assets). Capital outflow = net flow of investment out of the domestic economy.

Drivers of capital flows (what determines risk-adjusted returns): 1. The neutral rate r* (long-run fundamentals: productivity, demographics, fiscal position). 2. Monetary policy stance (short-term interest rate differentials). 3. Country risk (political stability, default risk, policy predictability).

Exchange Rate Regimes¶

Flexible exchange rate: E is determined by market supply and demand without government intervention. Most large economies (US, Eurozone, Japan) are approximately in this category.

Fixed exchange rate: The central bank sets a target for E and buys or sells foreign currency as needed to maintain it. Examples: Hong Kong, Singapore, Saudi Arabia, UAE.

• If the target E is above the market equilibrium: domestic currency is undervalued. Central bank must buy foreign currency (expanding domestic money supply).
• If the target E is below the market equilibrium: domestic currency is overvalued. Central bank must sell foreign reserves (contracting domestic money supply).

In reality, exchange rate regimes exist on a spectrum between fully flexible and rigidly fixed.

The Real Exchange Rate¶

The real exchange rate adjusts the nominal rate for price level differences, measuring the true relative cost of foreign vs. domestic goods:

Real Exchange Rate = E x (P* / P)

An increase in the real exchange rate means foreign goods are becoming more expensive relative to domestic goods (domestic goods are more competitive).

Approximation for changes:

% change in real exchange rate ≈ % change in E + pi* - pi

where pi and pi* are domestic and foreign inflation, respectively.

The Intuition: If the domestic currency depreciates by 10% but domestic inflation is 10% higher than foreign inflation, the real exchange rate is unchanged -- the nominal depreciation is fully offset by higher domestic prices. Competitiveness has not improved.

In the short run, nominal exchange rates are much more volatile than price levels, so changes in nominal exchange rates translate directly into real exchange rate movements.

Cross-reference: Exchange rates connect to Corporate Finance (foreign currency risk in international projects, cost of capital for multinational firms) and Operations Strategy (global supply chain decisions depend on real exchange rates determining relative production costs).

Lesson 9: Capital Flows and the Balance of Payments¶

Session 10. Reading: The Balance of Payments. Mini case: Norway oil.

The Big Idea¶

The balance of payments records all economic transactions between a country and the rest of the world. Its fundamental identity -- current account + financial account = 0 -- means that capital flows and trade flows are two sides of the same coin. If capital flows into a country (financial account surplus), that country must be running a current account deficit (importing more than it exports). The real exchange rate is the mechanism that links the two.

Balance of Payments Accounts¶

Current Account (CA): - Balance of payments on goods and services (exports minus imports). - Plus net international transfer payments and factor income.

Financial Account (FA): - Net sales of domestic assets to foreigners minus net purchases of foreign assets. - A financial account surplus = net capital inflow = deterioration of net foreign asset position.

The Identity:

Current Account + Financial Account = 0

Every international transaction enters the balance of payments twice (debit and credit). If a country imports a good (current account debit), it simultaneously exports currency or a financial claim (financial account credit).

The Link Between Savings, Investment, and Capital Flows¶

One of the main advantages of an open economy is that it decouples savings from investment:

• A country can invest more than it saves by borrowing from abroad (capital inflow --> current account deficit).
• A country can save more than it invests by lending to the rest of the world (capital outflow --> current account surplus).

Capital Flows Under a Flexible Exchange Rate¶

Suppose domestic risk-adjusted returns increase (e.g., central bank raises rates):

1. Capital flows in --> demand for domestic currency rises --> domestic currency appreciates (E falls).
2. Nominal appreciation --> real appreciation --> domestic goods become more expensive for foreigners, foreign goods become cheaper for domestic consumers.
3. Exports fall, imports rise --> current account deteriorates.
4. Current account deficit = mirror of the capital inflow (the identity holds).

Conversely, if domestic returns fall: 1. Capital flows out --> domestic currency depreciates (E rises). 2. Domestic goods become cheaper abroad --> exports rise, imports fall --> current account improves.

Capital Flows Under a Fixed Exchange Rate¶

The adjustment mechanism is different because the central bank prevents E from moving:

Capital inflow: 1. Foreign investors want domestic currency --> central bank sells domestic currency, buys foreign currency (to maintain fixed E). 2. Domestic money supply increases --> AD shifts right --> prices rise (boom). 3. Higher domestic prices --> real exchange rate appreciates even though nominal rate is fixed. 4. Exports fall, imports rise --> current account deteriorates.

Capital outflow: 1. Investors sell domestic currency --> central bank sells foreign reserves, buys domestic currency. 2. Domestic money supply contracts --> AD shifts left --> prices fall (recession). 3. Lower domestic prices --> real exchange rate depreciates. 4. Exports rise, imports fall --> current account improves.

Key difference: Under a flexible rate, adjustment happens quickly through the nominal exchange rate. Under a fixed rate, adjustment is slow and painful -- it requires domestic prices and wages to change, which takes time and causes economic volatility.

Back-of-the-napkin: "This country has a large current account deficit -- is that bad?" It depends. A current account deficit means the country is importing capital (borrowing). If that capital is funding productive investment (like Norway's oil infrastructure), it can be sustainable. If it is funding consumption, the debt must eventually be repaid, and the adjustment may be painful.

Lesson 10: Macroeconomic Policy in Open Economies¶

Session 12. Reading: Macroeconomic Policy in Open Economies. Mini case: Argentina dollar.

The Big Idea¶

Opening the economy to trade and capital flows fundamentally changes how monetary and fiscal policy work. The critical insight is the impossible trinity (also called the trilemma): a country cannot simultaneously maintain (1) free capital flows, (2) a fixed exchange rate, and (3) independent monetary policy. It must sacrifice one. This single principle explains most international monetary arrangements and policy failures.

Revisiting AD in an Open Economy¶

In an open economy, aggregate demand includes net exports:

AD = C + I + G + NX, where NX = X - M

Net exports add a new channel through which policy affects the economy -- the exchange rate channel.

The Impossible Trinity¶

A country must choose two of three:

Monetary Policy in a Small Open Economy¶

Flexible Exchange Rate: EFFECTIVE (but through a different channel)¶

1. Central bank lowers i_policy below r* (expansionary).
2. Domestic interest rates fall below the global rate.
3. Capital outflows --> domestic currency depreciates (E rises).
4. Depreciation makes exports cheaper, imports more expensive --> NX rises.
5. AD shifts right --> output recovers.

Note: In a perfectly open small economy, monetary policy works entirely through the exchange rate / net exports channel, not through investment (because domestic rates cannot fall below the global rate).

Fixed Exchange Rate: INEFFECTIVE¶

1. Central bank tries to lower i_policy (expansionary).
2. Capital outflows --> pressure for domestic currency to depreciate.
3. To maintain the fixed rate, central bank sells foreign reserves and buys domestic currency.
4. This reverses the money supply expansion, undoing the rate cut.
5. AD is unchanged. Monetary policy is neutralized.

Fiscal Policy in a Small Open Economy¶

Flexible Exchange Rate: INEFFECTIVE¶

1. Government increases spending (expansionary fiscal, primary deficit rises).
2. Domestic interest rates rise above the global rate.
3. Capital inflows --> domestic currency appreciates (E falls).
4. Appreciation makes exports more expensive, imports cheaper --> NX falls.
5. The decline in NX fully offsets the increase in G --> AD is unchanged.

Fixed Exchange Rate: EFFECTIVE (and amplified)¶

1. Government increases spending (expansionary fiscal).
2. Domestic interest rates rise --> capital inflows.
3. To prevent appreciation, central bank buys foreign currency, expanding domestic money supply.
4. This additional monetary expansion reinforces the fiscal stimulus.
5. AD shifts right through both fiscal AND monetary channels.
6. No crowding out (rates do not rise), no NX reduction (exchange rate is fixed).

Summary: Policy Effectiveness in Open Economies¶

This table assumes a small, perfectly open economy with free capital mobility. In practice, most economies fall between the extremes. For example, the US is large enough to influence global rates, so both monetary and fiscal policy have some effectiveness even under a flexible exchange rate.

When the Economy is Not Small or Capital is Not Perfectly Mobile¶

• Large economy (e.g., US): Expansionary monetary policy lowers global rates, so it works through both investment and NX channels. Fiscal expansion raises global rates, limiting capital inflows, so the NX offset is incomplete -- fiscal policy retains some effectiveness.
• Imperfect capital mobility: Domestic rates can diverge from global rates, giving monetary policy more traction even under fixed rates, and making fiscal policy partially effective under flexible rates.

Exchange Rate Fluctuations and SRAS¶

Under a flexible exchange rate, currency movements affect not just AD (through NX) but also SRAS (through imported input costs):

• Depreciation raises the cost of imported intermediate inputs --> SRAS shifts left (stagflationary pressure).
• Appreciation lowers imported input costs --> SRAS shifts right (deflationary boost to supply).

The magnitude depends on how much the country relies on imported intermediate inputs for production. Countries that import mostly final goods are less affected. This is why emerging markets that depend on imported raw materials sometimes resist currency depreciation even when it would boost exports.

Back-of-the-napkin: "Argentina dollarizes / fixes its exchange rate. What does it gain and lose?" Gains: elimination of currency risk, imported credibility for inflation control. Loses: independent monetary policy (cannot cut rates in a recession), and if the fixed rate becomes misaligned with fundamentals, adjustment requires painful deflation (internal devaluation) rather than a quick currency depreciation.

Cross-reference: The impossible trinity connects to Corporate Finance (hedging foreign currency exposure, evaluating country risk in international projects) and Operations Strategy (the exchange rate regime determines how global supply chain costs fluctuate).

Lessons 11-19: Country Cases (Module IV)¶

Sessions 13-21. Applied cases: Hong Kong, Sri Lanka, USA, Japan, Mexico, Chile, Eurozone, and surprise cases.

The Big Idea¶

Module IV is where theory meets reality. Each country case requires you to apply the full Global Economics toolkit -- micro and macro, closed and open economy, monetary and fiscal -- to diagnose a real economy, evaluate its policy choices, and predict what comes next. There is no new theory; the challenge is integration and judgment.

The Diagnostic Framework for Country Cases¶

When analyzing any country, work through these steps systematically:

Step 1: Identify the Institutional Setup - Exchange rate regime (fixed, flexible, or managed float)? - Degree of capital mobility (free, restricted, or somewhere in between)? - Central bank credibility (is the inflation target anchored)? - Fiscal position (debt-to-GDP ratio, primary deficit, interest burden)?

Step 2: Identify the Shock - Is it a demand shock or a supply shock (or both)? - Is it domestic or external (e.g., global commodity prices, foreign interest rates)? - Is it temporary or persistent?

Step 3: Trace Through the Framework - Use AD/AS to determine the short-run effects on output, prices, and unemployment. - Use the balance of payments identity to trace capital flows and current account effects. - Use the exchange rate framework to predict currency movements (or, under a fixed regime, the required central bank intervention).

Step 4: Evaluate the Policy Response - Given the institutional setup (especially the impossible trinity constraints), what policy tools are available? - Is the policy response appropriate for the shock? (e.g., monetary easing after a demand shock is straightforward; monetary easing after a supply shock risks inflation). - What are the medium-term consequences? (Debt accumulation? Loss of reserves? Inflation expectations unanchoring?)

Step 5: Assess Sustainability - Can the current trajectory continue, or does something have to give? - What are the risks? (e.g., reserve depletion under a fixed rate, debt spiral under expansionary fiscal policy, loss of credibility).

Quick Profiles of Key Country Cases¶

Hong Kong -- Tests: fixed exchange rate (currency board pegged to USD), free capital mobility, no independent monetary policy. The impossible trinity in pure form. How does Hong Kong adjust to shocks without its own monetary policy? (Answer: through domestic price and wage adjustment -- "internal devaluation.")

Sri Lanka -- Tests: fiscal crisis, debt sustainability, loss of central bank credibility. What happens when a country borrows too much, the central bank finances the deficit by printing money, and inflation spirals? How does an economy rebuild credibility?

USA -- Tests: large open economy. The US is large enough to influence global interest rates, so both monetary and fiscal policy retain effectiveness under a flexible exchange rate. How does the Fed manage the dual mandate (inflation + employment)?

Japan -- Tests: zero lower bound, deflation, unconventional monetary policy (QE), aging demographics lowering r*. What happens when monetary policy runs out of conventional ammunition?

Mexico -- Tests: emerging market with flexible exchange rate, high pass-through from exchange rate depreciation to inflation, capital flow volatility. How does an emerging market central bank balance growth and inflation credibility?

Chile -- Tests: commodity-dependent economy (copper), managed exchange rate, fiscal rules (structural balance rule). How does a country manage commodity price shocks?

Eurozone -- Tests: monetary union with heterogeneous member states. The ECB (European Central Bank) sets one interest rate for all. Countries give up independent monetary policy AND exchange rate flexibility. Fiscal policy is the only national tool, but is constrained by EU fiscal rules. How do individual Eurozone countries adjust to asymmetric shocks?

Quick Reference¶

1. Supply and Demand Three-Step Method: (1) Identify which curve shifts, (2) determine direction, (3) compare old and new equilibrium. Price + quantity both rise = demand shock; price rises but quantity falls = supply shock. → See: Lesson 1
2. Price Elasticity of Demand: Eᵈ = % change in Qᵈ / % change in P. More substitutes = more elastic. Inelastic demand + shock = big price swing; elastic demand + shock = big quantity swing. → See: Lesson 1
3. Price Controls: Binding ceiling (below p) creates shortage and deadweight loss. Binding floor (above p) creates surplus and deadweight loss. → See: Lesson 3
4. Tax Incidence: The burden falls on the more inelastic side, regardless of who legally pays. Deadweight loss grows with the square of the tax rate. → See: Lesson 4
5. GDP Identity: Y = C + I + G + NX. Real GDP (constant prices) isolates production changes. Nominal GDP = P x Y. → See: Lesson 5
6. Fisher Equation: rᵉ = i - piᵉ. Real interest rate = nominal rate minus expected inflation. The real rate governs economic decisions. → See: Lesson 5
7. AD/AS Framework: AD slopes down (wealth effect). SRAS slopes up (sticky wages). LRAS is vertical at potential output Y. Booms (Y > Y) self-correct via rising wages; recessions (Y < Y*) self-correct via falling wages, but slowly. → See: Lesson 5
8. Monetary Policy: Central bank sets nominal rate; what matters is real policy rate vs. neutral rate r. Below r = expansionary (AD right). Above r* = contractionary (AD left). → See: Lesson 6
9. Fiscal Policy: Expansionary = increase primary deficit (raise G, raise Tr, or cut T). Contractionary = decrease primary deficit. Crowding out partially offsets fiscal stimulus via higher interest rates. → See: Lesson 7
10. Impossible Trinity: Cannot have all three: free capital flows, fixed exchange rate, independent monetary policy. Must sacrifice one. → See: Lesson 10
11. Policy Effectiveness in Open Economies: Flexible exchange rate: monetary effective, fiscal ineffective. Fixed exchange rate: monetary ineffective, fiscal effective (and amplified). → See: Lesson 10
12. Real Exchange Rate: E x (P/P). Rising = domestic goods more competitive. % change ≈ % change in E + pi - pi. → See: Lesson 8
13. Balance of Payments: CA + FA = 0. Current account deficit = capital inflow = the country is borrowing from the world. → See: Lesson 9
14. Country Case Diagnostic: (1) Identify institutional setup, (2) identify the shock, (3) trace through AD/AS and BOP, (4) evaluate policy response, (5) assess sustainability. → See: Lesson 11

Formula Reference¶

Microeconomics¶

Macroeconomics¶

International Finance¶

Glossary of Key Terms¶

Cross-Reference Map¶