Fiscal Multiplier in a Small Open Economy

The fiscal multiplier in a small open economy is typically much smaller—often 0.4 to 0.7—than in closed or large economies because fiscal stimulus “leaks” abroad through imports and raises the exchange rate, crowding out export competitiveness. A country’s size and trade openness fundamentally change how fiscal spending multiplies through output.

Why small open economies are different

A large, relatively closed economy like the United States can run fiscal stimulus with relatively contained leakage. When a $100 billion spending boost enters the US economy, most of it recirculates through domestic production and wages. Imports are a minority of GDP, so the multiplier chain stays largely at home. Multipliers near 1.0 are plausible.

A small open economy like Belgium, Singapore, or Ireland faces a fundamentally different setting. High import propensity means that as incomes rise from fiscal stimulus, consumers and firms immediately spend a large fraction on foreign goods. Limited domestic production capacity means much of the stimulus demand cannot be met domestically and must be satisfied by imports. And integrated capital markets mean that a fiscal expansion financed by borrowing attracts inflows, appreciates the exchange rate, and hurts export competitiveness.

The result: multipliers often fall to 0.4 to 0.7, meaning a $100 billion stimulus raises output by only $40–70 billion. Nearly half the spending leaks away.

The import channel: demand for foreign goods

The most direct channel is the marginal propensity to import (MPI). When households and firms see higher incomes from fiscal stimulus, they spend on goods from abroad alongside domestic goods.

In a closed economy, all consumption and investment demand must be met by home production, so the multiplier is relatively large. In an open economy, part of that demand is satisfied by imports. This reduces domestic production and employment relative to the stimulus size.

Consider a stylised example. A government hires 1,000 workers to build a road. Those workers earn wages and spend 70% (the marginal propensity to consume). But suppose 40% of that consumption is on foreign cars, electronics, and food. Only 30 percentage points of the original 70% stimulates domestic producers, while 40 percentage points leaks to foreign suppliers.

Domestic producers then earn smaller incomes and hire fewer workers than they would in a closed economy. The subsequent rounds of spending are smaller, and the multiplier falls. Economies where imports are 40–50% of GDP—like Belgium or Ireland—experience severe leakage. Even a 0.7 multiplier is generous for such economies.

The exchange rate channel: crowding out exports

A second and often larger channel operates through capital flows and exchange rates.

When a government runs a fiscal deficit to finance stimulus, it typically borrows—selling bonds to domestic and foreign investors. This raises demand for the country’s currency (foreign investors need the local currency to buy bonds) and pushes up the exchange rate.

A stronger exchange rate makes the country’s exports more expensive for foreign buyers and imports cheaper for home consumers. Export-oriented firms face shrinking demand from abroad; they cut investment and hiring. Simultaneously, import-competing firms face cheap foreign competition and may shed jobs. The net effect is export crowding-out: fiscal expansion drives out private export revenue.

This channel can be larger than import leakage. Research on small open economies (Ireland, Denmark, New Zealand) suggests that half or more of a fiscal stimulus’s impact is offset by exchange-rate appreciation and the loss of export competitiveness. The multiplier can collapse toward 0.5 or below.

The mechanism depends on capital mobility. In a small developed economy with open capital markets (US Treasury bonds and eurodollar markets), a fiscal expansion is met almost instantly with foreign inflows, pushing the currency up within weeks. In a developing country with capital controls, the exchange rate channel is weaker and the multiplier may be slightly larger. But for most small developed economies, this channel is decisive.

Composition: when does the multiplier matter less?

Not all fiscal expansions hit small open economies equally hard. The type of spending matters.

Consumption stimulus (tax cuts, welfare increases) has the worst multiplier in small open economies because much of the extra income is spent on imports. Households in Belgium or New Zealand buying extra goods quickly turn to foreign suppliers. Multipliers near 0.4–0.5 are typical.

Investment stimulus (infrastructure, research subsidies) can do somewhat better—perhaps 0.6–0.8—because domestic construction and engineering firms are harder to outsource. But even infrastructure spending faces import leakage (imported machinery, foreign engineering firms) and the exchange-rate crowding-out effect.

Government spending on non-traded services (health, education, public administration) has the largest multiplier—potentially 0.7–0.9—because these services are inherently domestic. You cannot import a doctor’s visit or a school lesson. However, even this spending raises incomes that spill into imports, and it still attracts capital inflows and appreciates the currency.

Export-promoting spending (R&D, trade infrastructure, port upgrades) can sometimes exceed a multiplier of 1.0 if it shifts international competitiveness. But such spending is rare and uncertain in effect.

The policy implication: fiscal stimulus is weak

This analysis explains why economists are often sceptical of fiscal stimulus in small open economies. If your country is Ireland, Denmark, or New Zealand, a unilateral fiscal expansion leaks heavily to imports and gets offset by currency appreciation. The output gain is modest, but the trade deficit and public debt both worsen.

By contrast, a coordinated global stimulus—where all trading partners expand together—can be more effective. If Belgium and all its trading partners expand simultaneously, there is less exchange-rate pressure (no relative appreciation) and less competitive disadvantage. Import demand rises in other countries alongside demand for Belgian exports. The multiplier improves toward 0.7–0.9. This is why fiscal stimulus during global recessions (2008–2009, 2020) was partly justified: coordination and spillovers reduced the leakage problem.

Monetary policy is often more potent in small open economies. A central bank can cut rates, depreciate the currency, and boost exports without the immediate crowding-out that fiscal stimulus triggers. This is why many small developed economies have delegated fiscal policy to disciplined rules and rely on monetary policy for stabilisation.

Empirical evidence and cross-country variation

IMF and OECD studies consistently find that multipliers in small open economies are roughly half those in large economies. A meta-analysis of fiscal multipliers shows:

• Large closed or semi-closed economies (US, euro area as a whole, China): 0.8–1.2
• Larger open economies (UK, Canada, Australia): 0.6–0.9
• Small open economies (Ireland, Belgium, Denmark, New Zealand): 0.4–0.7

The correlation with trade openness is strong: countries where trade is more than 50% of GDP show multipliers near 0.5, while countries where trade is 25–30% of GDP show multipliers near 0.8.

Recent evidence from Europe (2010–2015 austerity period) confirmed that small open economies experienced very weak demand from fiscal consolidation. Countries like Ireland and Denmark, which cut spending sharply, saw smaller output declines than large economies did when cutting equivalent fractions of GDP. This is consistent with low multipliers: if your multiplier is 0.5, the pain from cutting is also half that of a large economy with a multiplier of 1.0.

Why this matters for policy design

Small open economies cannot rely on unilateral fiscal stimulus to manage recessions. Instead, they tend to:

1. Use monetary policy heavily—cutting rates, accepting currency depreciation, and boosting export competitiveness.
2. Coordinate with trading partners—negotiating simultaneous fiscal expansions or monetary easing to reduce relative-price shifts.
3. Target supply-side reform—improving productivity and competitiveness rather than trying to boost demand through deficit spending.
4. Maintain fiscal discipline—recognising that high public debt matters more when multipliers are low and debt reduction is slow.

A corollary: austerity in a small open economy is less contractionary than in a large economy, because the low multiplier cushions the demand shock. This is not an argument for austerity (debt sustainability still matters), but it explains why austerity in Ireland or Portugal hurt less in output terms than equivalent cuts would have in, say, Japan or the United States.

See also