When unemployment insurance (UI) taxes are incompletely experience rated, a self-financing UI system has to impose additional taxes that are exogenous to the behavior of individual firms. In the United States, these nonrated tax components vary predictably over the business cycle. A model of firm behavior under such a tax is presented. Evidence suggests signs for the parameters of the model that predict that incomplete experience rating, while (as shown elsewhere) increasing the rate of temporary layoffs, leads to the use of multiple tax schedules in a way that exerts downward pressure on cyclical swings in aggregate unemployment.

Previous studies of optimal unemployment insurance (UI) design ignore the impact of UI on human capital investment decisions. We show that fully experience-rated UI increases investment in human capital when future employment opportunities are not known with certainty. In the presence of wage taxation, the optimal level of UI trades off full insurance and the impact, through human capital, of UI on the wage tax base. This trade-off, in turn, depends on the extent to which human capital accumulation reallocates labor between market and untaxed nonmarket activities. Taxation of UI benefits increases the optimal level of UI provision.