Another common misperception is that there is some trade off between unemployment and inflation. Both Friedman and Phelps attacked this simplistic notion. Unemployment seems to have a "natural" (equilibrium) rate, which is determined by the structure and operation of the labour market and is consistent with stable inflation (NAIRU - Non Accelerating Inflation Rate of Unemployment).
NAIRU is not cast in stone. Employment subsidies, for instance, make low skilled workers employable and lower NAIRU. So do unilateral transfers which raise incomes. According to Phelps, big drops in unemployment need not greatly increase permanent inflation. Stiglitz calculated that America's NAIRU may have dropped by 1.5% due to increased competition in the markets for jobs and goods. These findings are supported by other prominent economists. Stiglitz concluded that NAIRU, in itself, is meaningless. It is the gap between the estimated NAIRU and the actual rate of unemployment that is a good predictor of inflation.