Natural Rate of Unemployment
Plain definition
The natural rate of unemployment is the unemployment rate that prevails when the economy is at full employment — consisting of frictional plus structural unemployment, with zero cyclical unemployment. It is also called the non-accelerating inflation rate of unemployment (NAIRU).
In economics
The natural rate is the benchmark for monetary policy: pushing unemployment below it typically accelerates inflation, while unemployment above it signals slack and disinflationary pressure. It shifts over time with demographics, labor-market institutions, and technology — U.S. estimates drifted from about 6% in the 1980s toward roughly 4% in the 2010s. Central banks aim to keep actual unemployment near it.
Example
If frictional unemployment is 2% and structural is 2%, the natural rate is 4%. When actual unemployment is 7% during a recession, the 3-point gap is cyclical unemployment — the part stimulus can erase. When actual unemployment is 3.5%, below the natural rate, inflation usually starts to pick up.
The natural rate is widely misread as 'zero unemployment' or as a fixed law of nature. It is neither: it is the unavoidable frictional-plus-structural baseline, and it moves with the economy's structure. NAIRU adds a specific claim — that below this rate, inflation accelerates — but the rate itself is an estimate, not a constant.