An economy with less than full employment in Beveridge's sense will have either classical unemployment, cyclical unemployment, or both. Classical unemployment results from the actual real wage rising above the equilibrium real wage, so that the quantity of labor demanded (and the number of vacancies) is less than the quantity of labor supplied (and the number of unemployed workers). This might occur because of inefficient interference in the market; for example, a minimum wage set above the equilibrium wage; but also because of market failure, such as that caused by cartels.