Full employment

In theory, it is possible to abolish cyclical unemployment by increasing the aggregate demand for products and workers. However, eventually the economy hits an "inflation barrier" imposed by the four other (supply-side) kinds of unemployment to the extent that they exist.

Some economists see the inflation barrier as corresponding to the natural rate of unemployment. The "natural" rate of unemployment is defined as the rate of unemployment that exists when the labor market is in equilibrium and there is pressure for neither rising inflation rates nor falling inflation rates. More scientifically, this rate is sometimes referred to as the NAIRU or the Non-Accelerating Inflation Rate of Unemployment

No matter what its name, this means that if the unemployment rate gets "too low," inflation will get worse and worse (accelerate) in the absence of wage and price controls (incomes policies). Others simply see the possibility of inflation rising as the unemployment rate falls. This is the famous Phillips curve.

One of the major problems with the NAIRU theory is that no-one knows exactly what the NAIRU is (while it clearly changes over time). The margin of error can be quite high relative to the actual unemployment rate, making it hard to use the NAIRU in policy-making.

Another, normative, definition of full employment might be called the ideal unemployment rate. It would exclude all types of unemployment that represent forms of inefficiency. This type of "full employment" unemployment would correspond to only frictional unemployment (excluding that part encouraging the McJobs management strategy) and would thus be very low. However, it would be impossible to attain this full-employment target using only demand-side Keynesian stimulus without getting below the NAIRU and suffering from accelerating inflation (absent incomes policies). Training programs aimed at fighting structural unemployment would help here.

To the extent that hidden unemployment exists, it implies that official unemployment statistics provide a poor guide to what unemployment rate coincides with "full employment".