The effectiveness of state enterprise zone programs was examined by using a hypothetical-firm model called the Tax and Incentives Model-Enterprise Zones (TAIM-ez) model to analyze the value of enterprise zone incentives to businesses across the United States and especially in the 13 states that had substantial enterprise zone programs by 1990. The study raised considerable doubts regarding state enterprise zone programs' benefits to states, businesses, and targeted workers. The following policy suggestions were offered: (1) exempt some percentage of zone income from state corporate income taxation; (2) think of enterprise zones as concentrations of the hard-to-employ, and base criteria for creating zones entirely on residents' demographics; and (3) integrate enterprise zones with transportation and social policy to provide better access to jobs for those most in need of them. (Forty-seven tables/figures are included. The following are among the items appended: detailed description of the TAIM-ez model; a comparison of the TAIM and TAIM-ez models; discussions of the tax elasticity of employment and fiscal break-even; information about the Standard Statistical Establishment List data; guidelines for translating enterprise zone boundaries and tax characteristics of zones; detailed study results; information on gravity-based commuting models; and a discussion of enterprise zones and commuting. The bibliography lists 162 references.) (MN)