Primary Balance

The primary balance is a government's total revenue minus its total spending, leaving out interest payments on the public debt. When revenue exceeds non-interest spending the government runs a primary surplus; when it falls short it runs a primary deficit. Finance ministries, the IMF, rating agencies and bond investors use it to judge whether a country's current policies are adding to or reducing its debt burden.

The primary balance differs from the headline budget balance, often just called the deficit, which includes interest. Separating the two matters because interest reflects decisions taken in the past and the level of interest rates, while the primary balance reflects today's tax and spending choices within the government budget. It is a core variable in debt sustainability analysis and a common target in IMF lending programmes.

Picture someone who took out a large loan years ago. Each month they earn a salary, pay for rent, food and transport, and then make a payment on the old loan. If their salary covers their living costs with some money left over, they have a "primary surplus", even if what is left is not yet enough to pay all the interest on the old loan.

The primary balance answers a simple question about a government: setting aside the bill for past borrowing, is it living within its means today? A country with a primary surplus is not adding new debt through current policy; whether its overall debt shrinks depends on how large that surplus is compared with the interest bill and the growth of the economy.

The primary balance is calculated as:

Equivalently, it is the overall balance plus interest payments. Suppose a government collects 40 (billion, or per cent of GDP), spends 38 on everything except interest, and pays 4 in interest. Its primary balance is $40 - 38 = +2$, a primary surplus of 2, while its overall balance is $40 - 42 = -2$, a deficit of 2. The country is running a deficit only because of its interest bill.

Economists link the primary balance to the path of the debt-to-GDP ratio. The standard approximation is:

• $d$ is the debt-to-GDP ratio at the start of the year.
• $\Delta d$ is the change in that ratio over the year.
• $r$ is the average nominal interest rate paid on the debt.
• $g$ is the nominal growth rate of GDP.
• $pb$ is the primary balance as a share of GDP (positive for a surplus).

Take a country with debt of 80% of GDP, paying an average interest rate of 5% while nominal GDP grows at 3%. The primary surplus needed just to keep the ratio stable is $\frac{0.05 - 0.03}{1.03} \times 80 \approx 1.55$ per cent of GDP. Any smaller surplus, or a primary deficit, lets the ratio rise. If growth instead outpaced the interest rate, as it did in many advanced economies during the 2010s, the same country could run a modest primary deficit and still see its debt ratio fall. The gap between $r$ and $g$ is therefore one of the most watched numbers in public finance, and it moved against many borrowers when rates rose from 2022.

• IMF programmes. Lending arrangements typically set quarterly floors for the primary balance. Pakistan's Extended Fund Facility, approved in September 2024, targets primary surpluses because the country's interest bill takes a large share of federal revenue.
• Euro area crises. Greece's bailout programmes after 2010 were built around primary surplus targets, which became a focus of the debate on austerity.
• Market analysis. Investors in government bonds compare the primary balance a country actually runs with the balance it would need to stabilize debt, as a gauge of sovereign risk and the likelihood of default.
• Structural measures. The cyclically adjusted primary balance removes the effect of the business cycle, since revenue falls and benefit spending rises in a recession; it is the closest single measure of the stance of fiscal policy.

The primary balance can flatter or mislead. One-off revenues such as privatization receipts or windfall taxes can create a temporary surplus. Inflation raises nominal revenue quickly while interest costs on fixed-rate debt adjust only as bonds are refinanced, so a surge in prices can improve the primary balance for a while. Off-budget liabilities, state-owned enterprise losses and guarantees (publicly guaranteed debt) may not appear at all. Finally, a target that looks sound in the debt arithmetic may be hard to hit if the cuts needed weaken growth, the effect captured by the multiplier effect. Sustained large primary surpluses are historically rare, which is why analysts treat plans that rely on them with caution when assessing the outlook for national debt.

• International Monetary Fund: Fiscal Monitor