Demand management: fiscal policy

The use of government spending (G) and taxation (T) to influence aggregate demand, output, and employment in the economy. It is a demand-side tool — fiscal changes shift the AD curve.

Increasing government spending (G↑) and/or cutting taxes (T↓). More disposable income → C rises. More G → AD shifts right. Used to close a deflationary (recessionary) gap — boost output and reduce unemployment. Leads to a budget deficit if spending exceeds tax revenue.

Direct tax: levied directly on income or wealth — the payer cannot pass the burden on (e.g., income tax, corporation tax). Indirect tax: levied on spending/goods — the burden can be passed to consumers through higher prices (e.g., VAT/GST, excise duties, tariffs).

Decreasing government spending (G↓) and/or raising taxes (T↑). Less disposable income → C falls. Less G → AD shifts left. Used to close an inflationary gap — reduce demand-pull inflation. Creates a smaller deficit or a budget surplus.

Current (recurrent) spending: day-to-day costs (wages, healthcare, welfare). Capital spending: investment in infrastructure (roads, hospitals, schools). Transfer payments: payments where no good or service is received in return (pensions, unemployment benefits, subsidies).

Progressive: tax rate rises as income rises (e.g., most income taxes). Regressive: takes a larger % from lower earners (e.g., flat-rate VAT — same rate, bigger share of a poor person's income). Proportional (flat): same % regardless of income.

Transfer payments (pensions, benefits, subsidies) do not involve the government purchasing goods or services — no output is produced. They redistribute income. They affect AD indirectly: when recipients spend transfer income, it increases C (consumption), not G.

Fiscal policy is implemented by the government (through parliament/congress passing spending and tax legislation). Monetary policy is implemented by the central bank (setting interest rates). Both shift AD, but through different channels and with different decision-making processes.

Progressive taxes take a higher percentage from higher earners, generating revenue that can be redistributed through transfers and public services to lower-income groups. This narrows the gap between rich and poor and shifts the Lorenz curve toward equality.

VAT is charged at the same rate on goods regardless of the buyer's income. Since lower-income households spend a larger proportion of their income on consumption, VAT takes a bigger share of their income compared to wealthier households who save more.

During a recession or deflationary gap — when output is below potential, unemployment is high, and AD is insufficient. The government increases G or cuts T to boost spending, shift AD right, and close the output gap.

G represents government spending on goods and services only — such as paying public employees, building infrastructure, and purchasing equipment. It does NOT include transfer payments like pensions or unemployment benefits.

Expansionary fiscal policy means G↑ or T↓ (or both). If the government spends more than it receives in tax revenue, it runs a budget deficit. The deficit must be financed by borrowing, which adds to the national debt.

Building roads, railways, hospitals, and schools; investing in renewable energy projects; constructing broadband networks. Capital spending increases the productive capacity of the economy and can shift both AD right (short run) and LRAS right (long run).

Direct taxes: income tax, corporation tax, capital gains tax, inheritance tax. Indirect taxes: VAT/GST, excise duties (on alcohol, tobacco, fuel), tariffs (on imports), environmental taxes (carbon tax). Direct taxes are on income/wealth; indirect taxes are on spending.

The idea that an initial change in spending (e.g., government investment) causes a larger final change in real GDP. Each round of spending becomes income for someone else, who then also spends part of it, creating successive rounds of income and spending.

The multiplier works both ways — a withdrawal (fall in G, I, or X) causes a multiplied contraction in GDP. If the government cuts spending by $50m with a multiplier of 4, GDP falls by $200m. This amplifies the effect of spending cuts.

Multiplier (k) = 1 / (1 − MPC) which equals 1 / MPS (marginal propensity to save). If MPC = 0.8, then k = 1 / (1 − 0.8) = 1 / 0.2 = 5. A $100m injection would increase GDP by $500m.

The fraction of each additional dollar of income that is spent on consumption. If MPC = 0.8, it means 80 cents of every extra dollar earned is spent. The remaining 20 cents is saved (MPS = 0.2). MPC + MPS = 1.

Government spends $100m building a hospital. Workers earn $100m. If MPC = 0.8, they spend $80m. Recipients of that $80m spend $64m (80%), and so on. Total GDP increase = $100m × multiplier (5) = $500m — much more than the initial injection.

The initial injection (e.g., G↑ of $100m) shifts AD right. With the multiplier, the FINAL shift of AD is larger (e.g., $500m if k = 5). The new equilibrium shows a larger increase in real GDP and price level than the initial stimulus alone would suggest.

In reality, multipliers are usually between 1 and 2 (not 4 or 5) because of high leakages (taxes, savings, imports, supply-side constraints). The simple formula ignores many real-world frictions like confidence effects, time lags, and crowding out.

No. The multiplier works for any injection into the circular flow — government spending (G), investment (I), or exports (X). It also works in reverse: a fall in any of these causes a multiplied contraction in real GDP.

Savings (S) — income saved is not re-spent. Taxes (T) — income taxed is withdrawn from the spending stream. Imports (M) — spending on imports leaks to foreign economies. The higher the leakages, the smaller the multiplier.

Austerity (cutting G or raising T) triggers the negative multiplier — the initial cut leads to a larger fall in GDP. This is why severe austerity during recessions can worsen the downturn rather than helping the economy recover.

An open economy has high imports — when people spend, a large share goes to foreign producers. This means more income leaks out at each round, leaving less to be re-spent domestically. Similarly, heavily taxed economies have smaller multipliers.

At each round, some income leaks out through savings, taxes, and imports. Each successive round of spending is smaller. Eventually the additional spending rounds become negligibly small and the process converges to the total multiplied effect.

It depends on where the economy is relative to full capacity. With spare capacity (flat SRAS), most of the shift becomes real GDP growth. Near full capacity (steep SRAS), most becomes inflation. The shape of SRAS determines the split.

That each round of spending becomes income for someone else, who then spends a fraction (MPC) and saves/taxes/imports the rest. The higher the MPC, the more is re-spent at each round and the larger the total multiplied effect on GDP.

k = 1 / (1 − 0.75) = 1 / 0.25 = 4. Total GDP change = $200m × 4 = $800m. The initial $200m injection creates $800m in total GDP through successive rounds of spending.

Budget deficit: government spending exceeds tax revenue in a given year — the shortfall must be financed by borrowing. Budget surplus: tax revenue exceeds government spending — the surplus can be used to repay debt. The deficit is a flow measure (this year's gap).

Built-in features of the tax and transfer system that automatically dampen economic fluctuations without any deliberate government action. Key examples: progressive income tax and unemployment benefits. They smooth the business cycle automatically.

When increased government borrowing (to finance a deficit) drives up interest rates, making it more expensive for the private sector to borrow and invest. The increase in G is partially offset by a fall in private I, reducing the effectiveness of expansionary fiscal policy.

The total accumulated amount a government owes from years of borrowing — the sum of all past budget deficits minus surpluses. It is a stock measure (total owed), unlike the deficit which is a flow (this year's shortfall).

Incomes fall → people pay less income tax (progressive tax: lower income = lower rate). More people claim unemployment benefits. Both cushion disposable income → C doesn't fall as sharply → the AD contraction is softened without any policy decision.

Political constraints (tax hikes unpopular), time lags (slow to identify, legislate, and implement), crowding out (borrowing → higher rates → less I), rising national debt, potential government inefficiency, and inflationary risk if used near full employment.

The deficit is a flow (this year's shortfall between spending and revenue). The debt is a stock (total accumulated borrowing over time). A government can have a small deficit but a large debt built up over decades of persistent deficits.

Incomes rise → people pay more income tax (progressive: higher income = higher rate). Fewer claim unemployment benefits. Both constrain disposable income growth → C doesn't rise as fast → the AD expansion is softened, reducing inflationary pressure.

Can target specific sectors or regions (unlike monetary policy). Effective when monetary policy hits the zero lower bound (liquidity trap). Automatic stabilisers smooth the cycle without lag. Can address inequality directly through progressive taxation and transfers.

High debt means large interest payments — reducing money available for public services (opportunity cost). It may reduce investor confidence, push up borrowing costs, and limit the government's ability to use fiscal policy during future crises.

In a liquidity trap, interest rates are near zero and monetary policy is ineffective (people hoard cash rather than borrow). Fiscal policy — directly increasing G or cutting T — can still boost AD because the government itself spends, bypassing the broken monetary transmission mechanism.

Automatic stabilisers are built into the system and activate without any policy decision (e.g., progressive tax, benefits). Discretionary fiscal policy requires deliberate government action — passing new legislation to change G or T. Automatic stabilisers have no decision lag.

They smooth the business cycle without any decision lag — they kick in immediately as conditions change. This avoids the time lag problem of discretionary policy (identifying the problem, passing legislation, implementing changes). They work every time, automatically.

Tax increases are deeply unpopular with voters, so politicians avoid them even when contractionary policy is needed. Spending projects may be directed to politically favourable areas rather than where they're most needed. Short election cycles encourage short-term thinking over sound fiscal management.

Japan's debt exceeds 260% of GDP — the highest in the developed world. US debt surpassed $34 trillion in 2024. Both ran persistent deficits, especially after the 2008 crisis and COVID-19 stimulus programmes.

The multiplier shows how an initial change in spending leads to a LARGER final change in GDP. Basic formula: k = 1 / (1 − MPC) = 1 / MPS, where MPC = marginal propensity to consume. If MPC = 0.8, k = 1/(1−0.8) = 1/0.2 = 5. A $100m injection → $500m increase in GDP.

Government spends $100m on roads → construction workers earn $100m → they spend 80% = $80m at shops → shop workers earn $80m → spend 80% = $64m → ... Each round, spending 'leaks' out (savings, tax, imports) but the remainder is re-spent. Total = $100m + $80m + $64m + ... = $500m (geometric series).

Larger MPC → larger multiplier (more re-spending per round). Smaller withdrawals (savings, taxes, imports) → larger multiplier. In the open economy formula: k = 1/(MPS + MPT + MPM). Higher MPS, MPT, or MPM → smaller k. Developing countries often have larger multipliers (less leakage to imports).

MPC = ΔC/ΔY (fraction of extra income spent on consumption). MPS = ΔS/ΔY (fraction saved). MPT = ΔT/ΔY (fraction taken as tax). MPM = ΔM/ΔY (fraction spent on imports). They sum to 1: MPC + MPS + MPT + MPM = 1 (approximately, in a simplified model with MPC capturing only domestic consumption).

MPS = 1 − MPC − MPT − MPM = 1 − 0.6 − 0.15 − 0.1 = 0.15. Or: k = 1/(1 − MPC_domestic) where leakages = MPS + MPT + MPM = 0.15 + 0.15 + 0.1 = 0.40. k = 1/0.40 = 2.5. So a $100m injection → $250m increase in GDP.

A higher MPM means more of each spending round LEAKS OUT to imports rather than being re-spent domestically. Imports are WITHDRAWALS from the circular flow — money flows abroad rather than creating domestic income. Small open economies (like Singapore) tend to have high MPM → small multiplier.

The negative multiplier works in the SAME WAY but in reverse. A WITHDRAWAL from the circular flow (e.g. cut in government spending, fall in investment, rise in taxes) leads to a MULTIPLIED fall in GDP. ΔY = k × (−ΔG). If k = 5 and G falls by $20m → GDP falls by $100m.

1) TIME LAGS: spending takes time to flow through. 2) Spare capacity needed (near full employment → inflation, not real growth). 3) Confidence: households may SAVE more during uncertainty (lower MPC). 4) Crowding out: government borrowing → higher interest rates → less private investment. 5) Supply constraints.

KEYNESIANS: emphasise the multiplier — government spending effectively boosts GDP, especially in recessions (spare capacity, high MPC from transfers to the poor). CLASSICAL/MONETARIST: multiplier is small in practice due to crowding out, Ricardian equivalence (households save more anticipating future taxes), and long-run LRAS being vertical.