Using a simple overlapping generations model with the growth engine of public capital by incorporating the union wage setting, we examine the effects of fiscal policies on unemployment, economic growth and welfare in the imperfect labor market. We demonstrate that the growth-maximizing tax in the imperfect labor market is larger than that of the perfect labor market. However, as the allocation ratio of public capital increases, the growth-maximizing tax in the imperfect labor market approaches that of the perfect labor market, thus reducing the unemployment rate. The policy implications of the intergenerational welfare aspects are also mentioned.