Output Gap

What Is an Output Gap?

An output gap measures how far an economy is operating from its productive capacity. Actual output is the total value of goods and services produced in a period, usually measured as gross domestic product (GDP). Potential output is the level of output an economy can sustain over time without generating rising inflation, given its labor force, capital, and technology.

When actual output is above potential, the gap is positive, meaning the economy is running hot and may face upward pressure on prices. When actual output is below potential, the gap is negative, indicating slack such as idle workers and unused factories.

How It Is Calculated

Output Gap (%) = (Actual GDP − Potential GDP) ÷ Potential GDP × 100

Because potential output cannot be observed directly, economists estimate it using statistical filters, production function models, or survey-based methods. Different estimates can produce noticeably different gaps, and figures are often revised as new data arrives. The output gap is therefore a model-dependent estimate rather than a precise reading.

An Example and Why It Matters

Suppose a hypothetical economy has an estimated potential GDP of 1,000 and actual GDP of 980, in any currency. The output gap is (980 − 1,000) ÷ 1,000 × 100, or −2%, which suggests spare capacity.

Central banks and governments watch the output gap when deciding whether to tighten or loosen monetary policy and fiscal policy. A persistently positive gap may suggest that demand is outpacing supply, while a negative gap may point to weak demand. The gap is closely related to labor market slack, so economists often compare it with the unemployment rate.

Limitations for Readers

Financial commentary often cites the output gap when discussing where an economy sits in the business cycle. Because it depends on an estimate of potential output, its value can change substantially depending on the method used, and early readings are often revised. It is one indicator among many and does not by itself predict market movements or recessions.