Monetary policy makes borrowing cheaper and hopes somebody spends. Fiscal policy skips the hoping: the government spends the money itself, or leaves more of it in your pocket by cutting tax. That directness is its great strength — and the reason it is so hard to reverse.
📚 What you need to know
Fiscal policy uses government spending and taxation to influence aggregate demand.
Expansionary: cut taxes or raise spending, shifting AD right. Contractionary: raise taxes or cut spending, shifting AD left.
A budget deficit means spending exceeds revenue; a surplus the reverse; a balanced budget means they are equal.
Deficits are financed by public sector borrowing, which adds to the public debt.
Government spending splits into current, capital and transfer payments. Transfers are not part of G in the AD formula.
The multiplier means an injection raises AD by more than itself: k = 1 ÷ MPW, where MPW = MPS + MPT + MPM.
Fiscal policy can be targeted at a region, industry or income group in a way monetary policy cannot.
The budget: revenue, spending and the gap between
Every year the government sets out what it expects to raise and what it plans to spend. The difference between those two numbers is the budget balance, and it is the single figure that shapes the whole fiscal debate.
A deficit is a flow measured over one year. The public debt is the stock built up from every past deficit — the same stock-and-flow distinction as income and wealth.
WORKED EXAMPLE
Revenue is $420bn, spending is $465bn, GDP is $1,500bn and public debt at the start of the year was $900bn. Calculate the deficit as a share of GDP and the new debt-to-GDP ratio. [4]
Step 1: the budget balance465 − 420 = $45bn deficitStep 2: as a share of GDP(45 ÷ 1,500) × 100 = 3.00%Step 3: the new debt stock900 + 45 = $945bnStep 4: the new ratio(945 ÷ 1,500) × 100 = 63.00%, up from 60.00%Deficit 3.00% of GDP; debt rises to 63.00% of GDPNote that the ratio would have fallen if GDP had grown faster than the debt. Growth is a way of reducing debt without cutting spending at all.
Where the money comes from and goes
Side of the budget
Category
Examples
Revenue
Direct taxes
Income tax, corporation tax, capital gains tax, inheritance tax
Revenue
Indirect taxes
VAT and excise duties on fuel, alcohol and tobacco
Revenue
Other sources
Charges by state-owned firms, and one-off receipts from privatisation
Spending
Current expenditure
Day-to-day running costs: public sector salaries, medicines, fuel for buses
Spending
Capital expenditure
Investment in infrastructure: railways, hospitals, schools, energy networks
Spending
Transfer payments
Benefits, pensions and subsidies, where no good or service is received in return
Transfer payments are not government spending in the AD formula. No output is produced, so nothing is added to G. They still affect AD, but indirectly, by raising household income and therefore consumption. Getting this right separates a Level 3 answer from a Level 2 one.
Expansionary fiscal policy
When output is below full employment, the government can close the gap by spending more or taxing less. Higher G raises AD directly. Lower income tax raises disposable income and therefore consumption; lower corporation tax raises retained profit and therefore investment.
Contractionary fiscal policy is the mirror image: AD shifts left, the price level falls and output drops back from an inflationary gap.
Policy
Instrument
Chain of effects
Expansionary
Cut income tax
Disposable income rises → consumption rises → AD shifts right → output and employment rise, prices rise
Expansionary
Raise capital spending
Government orders goods and hires firms → G rises directly → AD shifts right → and capacity rises later too
Contractionary
Raise income tax
Disposable income falls → consumption falls → AD shifts left → inflation eases, unemployment may rise
Contractionary
Freeze public sector pay
Real wages fall → consumption falls → AD shifts left → price pressure eases, growth slows
The multiplier: why $6bn becomes $12bn
Government spending does not stop when the government has spent it. The builders paid to construct a school spend their wages in local shops; the shopkeepers spend some of that too. Each round is smaller, because some money leaks out into saving, taxation and imports, but the total effect is bigger than the original injection.
The multiplier
k = 1 ÷ MPW where MPW = MPS + MPT + MPM
Change in AD = injection × k
The bigger the leakages, the smaller the multiplier. An economy that imports heavily or taxes heavily gets less bang for each fiscal buck.
WORKED EXAMPLE
MPS = 0.10, MPT = 0.25 and MPM = 0.15. The government raises capital spending by $6bn. Calculate the multiplier and the total change in AD. [3]
Step 1: add the leakagesMPW = 0.10 + 0.25 + 0.15 = 0.50Step 2: find the multiplierk = 1 ÷ 0.50 = 2Step 3: apply it to the injectionChange in AD = $6bn × 2 = $12bnMultiplier 2; AD rises by $12bnCheck it against MPC: if half of every extra pound leaks out, MPC = 0.5, and 1 ÷ (1 − 0.5) also gives 2.
The multiplier works in both directions. A $6bn spending cut with the same leakages reduces AD by $12bn. That is why austerity in a weak economy can shrink output by far more than the amount saved.
What fiscal policy is aiming at
Low and stable inflation — contractionary policy cools an overheating economy.
Low unemployment — expansionary policy raises AD, and firms hire to meet it.
Steady growth and a smoother cycle — leaning against booms and slumps.
A fairer distribution of income — progressive taxes and transfers, which monetary policy cannot do at all.
A sustainable current account — contractionary policy reduces import demand.
Higher productive capacity — capital spending raises LRAS in the long run, a supply-side bonus on a demand-side policy.
The best kind of government spending is often said to be spending that raises AD today and LRAS tomorrow. Building a rail link creates jobs and orders immediately, then permanently lowers transport costs. Use this example whenever you need to link fiscal and supply-side policy.
💡 Exam tip
State which instrument you are using — spending or tax — and which component of AD it moves.
Use the multiplier whenever you have MPS, MPT and MPM in the data. It is a quick, high-value calculation.
Keep deficit (a yearly flow) and debt (an accumulated stock) separate. Examiners test this constantly.
Remember that transfer payments do not enter G directly, but do raise C.
Mark the output gap on your AD/AS diagram and label it. That single arrow often carries a mark.
Debt-to-GDP can fall through faster growth as well as through spending cuts — a strong evaluation line.
⚠ Common mix-up
Deficit and debt. Cutting the deficit still adds to the debt, just more slowly.
Adding transfer payments to G. They are income moved around, not output bought.
Confusing expansionary fiscal policy with a balanced budget. Expansionary usually means running a bigger deficit.
Using 1 ÷ MPC as the multiplier. The formula is 1 ÷ MPW, or equivalently 1 ÷ (1 − MPC).
Forgetting the multiplier works downwards. Cuts contract AD by more than the amount cut.
Treating tax cuts and spending rises as identical. Spending enters AD in full; part of a tax cut is saved or spent on imports.
Up next: Evaluating Fiscal Policy — automatic stabilisers, crowding out, and why the politics is often the binding constraint.
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