The Econ Ace

How Does the Circular Flow Work?

One person's spending becomes another person's income.

How Are GDP and GNI Measured?

GDP measures production within a country; GNI adjusts it for residents' net income from abroad.

What Do Real GDP and GDP per Person Tell Us?

Remove price changes to measure real output, then divide by population to measure output per person.

How Can We Compare Purchasing Power?

A PPP conversion compares what incomes can buy at local prices.

Why Does Economic Activity Rise and Fall?

The business cycle describes changes in actual output around its longer-term path.

Does Higher GDP Mean Better Living Standards?

GDP measures production, not well-being directly.

3.2 Aggregate demand and supply

Progress loading…

What Is Aggregate Demand?

Aggregate demand is planned spending on domestic output at each price level.

Why Does Short-Run Aggregate Supply Shift?

SRAS reflects production decisions while some input prices adjust slowly.

What Determines Potential Output?

Potential output depends on resources and productivity.

How Does the Neoclassical Model Restore Equilibrium?

In this model, wage and cost adjustment brings output back to potential after a demand shock.

How Does Keynesian Aggregate Supply Work?

The Keynesian model links demand's effect to spare capacity.

How Can We Identify an Output Gap?

An output gap compares actual production with sustainable capacity.

3.3 Macroeconomic objectives

Progress loading…

What Are Macroeconomic Objectives?

Governments balance growth, employment, stable prices, sound public finances, external balance and wider living standards.

What Is Economic Growth?

Actual growth means producing more; potential growth means being able to produce more sustainably.

How Does Growth Affect Living Standards?

Growth can support consumption, jobs and public services, but its welfare effect depends on who gains and what resources or environmental quality are sacrificed..

How Is Unemployment Measured?

The unemployment rate counts jobseekers relative to the labour force.

Why Are People Unemployed?

Job search, skills mismatch, seasonal changes and weak overall spending create different kinds of unemployment.

What Do Inflation and the CPI Measure?

Inflation is a rise in the general price level.

What Causes Inflation?

Stronger demand can raise prices by pressing against capacity; higher production costs can raise prices while reducing output.

Why Can Falling Prices Be a Problem?

Falling prices can reflect better production or collapsing spending.

How Is a Weighted Price Index Calculated?

A weighted index gives more influence to items that take a larger spending share.

How Can We Assess Government Debt?

A deficit is a yearly flow; debt is an accumulated stock.

What Do Phillips Curves Show?

The short-run Phillips curve describes a conditional inflation–unemployment trade-off.

3.4 Inequality and poverty

Progress loading…

What Is Economic Inequality?

Income is a flow, wealth is a stock, and equality is different from fairness.

How Do Lorenz Curves and Gini Coefficients Work?

A Lorenz curve shows cumulative income shares from poorest to richest.

How Do We Draw a Lorenz Curve from Quintiles?

Add each quintile's income share to all earlier shares before plotting.

How Is Poverty Measured?

Absolute poverty concerns minimum needs; relative poverty compares resources with prevailing living standards.

Why Does Inequality Persist?

Skills, ownership, institutions and unequal opportunities can reinforce income differences.

How Do Taxes Affect Income Distribution?

Progressivity depends on the share of income paid, not the cash amount alone.

How Are Income Tax and Sales Tax Calculated?

Tax each income slice at its own marginal rate.

How Can Transfers and Public Services Reduce Poverty?

Transfers protect purchasing power now; accessible, effective services can improve future earning opportunities.

How Can Policy Support Incomes and Fair Access to Work?

Universal payments, wage floors and anti-discrimination measures reach different groups.

3.5 Monetary policy

Progress loading…

What Is Monetary Policy?

Monetary policy changes financial conditions to influence spending and inflation.

How Do Banks Create Money and Central Banks Influence Lending?

A commercial-bank loan creates a matching deposit, but capital, liquidity, risk and credit demand limit lending.

How Is Interest Determined in the Money-Market Model?

In the simplified money market, equilibrium balances desired money holdings with a given supply.

How Do Interest Rates Affect Spending?

Interest rates influence borrowing, saving, assets and exchange rates.

When Is Monetary Policy Effective?

Monetary policy works through responses by lenders, borrowers and savers.

3.6 Fiscal policy

Progress loading…

What Is Fiscal Policy?

Fiscal policy uses government spending and taxes to influence demand, distribution and productive capacity.

How Does Fiscal Policy Change Aggregate Demand?

Government purchases affect demand directly; taxes and transfers work through recipients' spending.

How Does the Keynesian Multiplier Work?

An injection becomes income that is partly spent again.

What Is Crowding Out?

Public borrowing can reduce private spending through higher financing costs or competition for scarce resources.

How Do Automatic Stabilizers Work?

Existing tax and benefit rules cushion income changes without a new policy decision.

When Is Fiscal Policy Effective?

Fiscal policy can target demand and public needs directly, but timing, financing and delivery determine whether it helps.

3.7 Supply-side policies

Progress loading…

What Are Supply-Side Policies?

Supply-side policies aim to improve productive ability, rather than simply create customers.

How Do Labour Reforms and Tax Incentives Affect Supply?

Changes to labour rules and taxes work through incentives and access to work or investment.

How Do Education and Health Improve Productive Capacity?

Education, relevant training and healthcare can improve what workers can do.

How Do Infrastructure and Innovation Raise Productivity?

Public support can remove bottlenecks and encourage useful knowledge creation.

How Should We Evaluate a Supply-Side Policy Package?

Choose policies that address the binding production constraint and coordinate their timing.

4.1 Benefits of international trade

Progress loading…

International trade is the exchange of goods and services between economies. Suppose a local shop buys a bicycle made abroad. The bicycle is an import for the shop's economy and an export for the producer's economy. These are two descriptions of the same sale, not different types of product.

How Does Trade Create Gains and Adjustment Costs?

Suppose a bakery imports an oven that uses less energy per loaf. Its production costs fall, creating scope for lower prices, higher wages or profits. Consumers also gain access to goods and varieties unavailable at home. The benefit depends on firms using the technology effectively and passing on some gains.

Open lesson →HL ONLY · 10 MIN

How Do World Prices Determine Imports and Exports?

Autarky means no international trade. Put price per unit vertically and quantity per period horizontally. Domestic demand D slopes down and supply S slopes up. Their intersection E is the no-trade equilibrium. Pw denotes the world price, which a small price-taking country cannot materially change.

What Is Comparative Advantage?

Absolute advantage means producing more with the same resources. Comparative advantage means producing at a lower opportunity cost, the alternative output given up. A country can have absolute advantage in both goods yet still gain by specialising where its relative advantage is greater.

Open lesson →HL ONLY · 10 MIN

How Do We Calculate Gains from Specialisation and Trade?

Keep the previous example: A can make 40 wheat or 20 cloth, and B 30 wheat or 30 cloth. A's cost of cloth is 2 wheat per cloth; B's is 1. A wants to buy cloth for less than 2 wheat, while B wants to receive more than 1 wheat for it.

4.2 Types of trade protection

Progress loading…

What Is Trade Protection?

Trade protection means government measures that shelter domestic producers from foreign competition. Under free trade, buyers can access imports without barriers such as tariffs or quotas. In the small-country model, a world price below the domestic no-trade price makes the country an importer.

How Do Import Tariffs Work?

A tariff is a tax on imported units. Assume a small price-taking economy, competitive sellers and no transport costs. Pw is the world price in dollars per unit. With a 5-dollar tariff on a product costing 20 abroad, importers need 25 to cover both the product and tax. Domestic sellers can also charge 25 while imports continue.

How Do Import Quotas Work?

An import quota sets a maximum quantity entering the country. It is binding only if below imports that would occur without it. At the old world price, a binding limit leaves buyers wanting more than domestic firms plus permitted imports can supply. The domestic price rises until the remaining gap matches the quota.

How Do Domestic Production Subsidies Work?

A domestic production subsidy is a payment for each eligible unit made at home. In the small importing-country model, foreign supply remains available at the world price, Pw. Consumers can still buy at Pw, so the subsidy need not raise their price.

How Do Export Subsidies Work?

Start with an exporting country: at the world price, domestic supply exceeds domestic consumption. An export subsidy pays firms only on the units sold abroad. This differs from paying for every unit produced at home.

How Do Administrative Barriers Affect Trade?

Administrative barriers are procedures such as licensing, labelling, product testing and inspections that can make importing harder. An importer must pay compliance costs or wait before selling. Some suppliers may withdraw, and buyers may face higher delivered prices or less choice.

How Do We Calculate the Costs of Trade Protection?

Let P be dollars per unit, Qd domestic demand and Qs domestic supply in thousands of units per month. Use Qd = 120 − 2P and Qs = 2P. The coefficient 2 means a one-dollar price change changes quantity by two thousand units. Pw is world price. Multiplying price by these quantities gives thousand dollars per month.

4.3 Arguments for and against trade protection

Progress loading…

Why Do Governments Protect Trade?

The previous section explained how barriers support some domestic producers while imposing costs elsewhere. Governments may accept those costs to protect employment, develop new industries, preserve essential production or address health and environmental risks. This section asks when those aims justify a particular measure.

When Can Trade Protection Be Justified?

An infant industry may learn through production and spread knowledge to other firms. Private returns can then fall below the wider benefit, giving a case for temporary assistance. Require evidence of that spillover, performance conditions and an exit plan; otherwise firms may lobby for permanent shelter.

4.4 Economic integration

Progress loading…

What Is Economic Integration?

Economic integration is closer cooperation between economies through reduced barriers and shared rules. Suppose two neighbours remove tariffs on each other's products. Firms can reach a larger market and buyers may obtain cheaper goods. Producers also face stronger competition from their partner's firms.

How Do Trade Agreements and Trading Blocs Differ?

A bilateral agreement has two parties; a regional agreement covers a group of economies; multilateral negotiation involves many participants. These descriptions concern participation, while terms such as customs union describe what is shared.

What Does the World Trade Organization Do?

The World Trade Organization, WTO, provides a framework for negotiated trade commitments, a forum for negotiations, monitoring and mechanisms for handling disputes. Its remit includes trade in goods and services and related rules. It is not a government setting every country's policy.

What Are Trade Creation and Trade Diversion?

Trade creation occurs when removing a barrier replaces higher-cost domestic output with cheaper partner imports. Suppose the domestic resource cost is 15 currency units per item and a partner can supply at 10. Removing the tariff that kept the partner out can save 5 in resources for each replaced domestic unit. Lower prices may also expand consumption.

What Are the Benefits and Costs of a Monetary Union?

A monetary union shares monetary arrangements, including a common currency in the model considered here. Members avoid exchanging currencies for transactions with each other and can compare prices more easily. Removing internal exchange-rate risk can encourage cross-border contracts and investment. A credible common central bank may also support stable inflation expectations.

4.5 Exchange rates

Progress loading…

What Is an Exchange Rate?

An exchange rate tells us how much of one currency buys one unit of another. A quote of 0.80 US dollars per domestic unit means one domestic unit buys USD 0.80. The words per domestic unit matter as much as the number. Reversing the quote produces a different number for the same exchange opportunity.

How Do We Convert Currencies and Measure Exchange-Rate Changes?

At 0.80 EUR per USD, one US dollar buys 0.80 euros. To convert dollars to euros, multiply the dollar amount by euros per dollar. A payment of USD 250 becomes EUR 200. To convert euros to dollars, divide by 0.80: EUR 200 buys USD 250 before fees.

Why Does a Currency Rise or Fall in Value?

The diagram trades domestic currency. Its horizontal axis measures domestic units traded per period; its vertical axis is foreign currency per domestic unit. Demand slopes down and supply up. E1 is their initial intersection, where planned purchases equal sales.

How Do Exchange Rates Affect Prices and Output?

Depreciation means each domestic unit buys less foreign currency. Suppose a machine costs USD 1,000. At USD 0.50 per domestic unit, its domestic price is 1,000 ÷ 0.50 = 2,000. After a fall to USD 0.40 per domestic unit it costs 2,500, assuming the dollar price is unchanged.

How Are Fixed and Managed Exchange Rates Maintained?

A floating rate changes with currency demand and supply. A fixed rate commits authorities to a stated parity. Managed floating allows the rate to move while authorities intervene to influence it, sometimes within a band. Stable data alone do not identify the arrangement: ask what officials promise to maintain.

How Can We Compare Exchange-Rate Systems?

A credible fixed rate reduces uncertainty for trade receipts and foreign-currency contracts. Pegging to a low-inflation currency may also help anchor inflation expectations. The benefit depends on confidence that the authorities can maintain the commitment.

4.6 Balance of payments

Progress loading…

What Is the Balance of Payments?

The balance of payments records transactions between residents of an economy and non-residents over a period, usually a quarter or year. Residency concerns a person's or organisation's centre of economic interest, not simply nationality. The record helps explain foreign receipts, external payments and how the economy finances a gap.

What Goes in the Current Account?

The current account groups cross-border production, income and current transfers. In these examples a credit records a receipt from a non-resident and a debit a payment to one. Exporting locally made cars is a goods credit; importing fuel is a goods debit.

How Do We Calculate the Current Account Balance?

Let CA mean current-account balance, G net goods, S net services, PI net primary income and SI net secondary income. Here G means goods, not government purchases in the macro spending formula. CA = G + S + PI + SI. Every term must be a flow in the same currency, scale and period.

How Do the Capital and Financial Accounts Connect?

The capital account includes capital transfers, such as qualifying debt forgiveness, and transactions in non-produced, non-financial assets, such as resource rights. Imported equipment remains a goods import, despite the everyday phrase capital goods.

Why Do Persistent Current-Account Imbalances Matter?

More imports can mean more sales of domestic currency to buy foreign currency. Stronger exports can create demand for domestic currency. A deficit does not mechanically cause depreciation, because foreign investment and borrowing may simultaneously raise demand for domestic assets and currency.

Open lesson →HL ONLY · 10 MIN

How Can Policy Reduce a Current-Account Deficit?

Expenditure switching redirects spending from foreign towards domestic output. Depreciation or devaluation changes relative prices; tariffs can deter imports but raise input costs and risk retaliation. Switching works poorly when imports are essential or domestic firms cannot expand.

Why Can the Trade Balance Worsen After Depreciation?

Trade balance means export revenue minus import expenditure in the stated currency. Each payment depends on price times quantity. After depreciation, unchanged foreign prices cost more domestic currency. Existing contracts and few substitutes may keep import quantities fixed initially.