What is Okun's law?

Okun's law, named after economist Arthur Okun who first described it in 1962, is an empirical relationship between changes in the unemployment rate and changes in real GDP. The most commonly cited version states that for every 1 percentage point increase in the unemployment rate above its natural rate, real GDP falls approximately 2 percentage points below its potential. Alternatively, in its "difference" form, a 1 percentage point increase in unemployment is associated with approximately 2% lower GDP growth.

The relationship is not a law in the physics sense but rather a robust empirical regularity. The approximate 2:1 ratio (the "Okun coefficient") reflects the fact that GDP losses from rising unemployment are amplified by several factors: firms reduce hours for remaining workers (productivity per worker falls), discouraged workers leave the labor force (reducing the measured unemployment increase while still reducing output), and reduced income causes multiplier effects that decrease spending and production across the economy.

The Okun coefficient has varied over time and across countries, typically ranging from 1.5 to 3.0 for the United States depending on the sample period and estimation method. During the 2008-2009 recession, the coefficient was larger than average, meaning each point of unemployment rise was associated with a larger GDP loss. During the COVID recession, the relationship broke down temporarily because the GDP decline was driven by deliberate lockdowns rather than the normal business cycle, and the rapid recovery did not follow the usual Okun pattern.

For practical macro analysis, Okun's law serves as a consistency check. If an analyst projects 3% GDP growth, Okun's law implies unemployment should be falling by roughly 0.5-1.0 percentage points. If the same analyst also projects rising unemployment, the GDP forecast is internally inconsistent. The relationship also helps translate between the labor market and output frameworks that different policymakers emphasize: the Fed focuses on unemployment (dual mandate), while fiscal policymakers focus on GDP growth, and Okun's law provides the bridge between these perspectives.