Description of a Welfare Policy Model that can be used to quickly and inexpensively calculate and summarize the economic effects of policy changes in the welfare and income tax systems in New York City. The model facilitates comparisons of alternative welfare and income tax policies, identifies and counts those eligible for welfare under the different policies, and estimates the impact of alternative policies on budgetary costs, the size and sociodemographic composition of the welfare-eligible population, and the distribution of income. Six alternative policies are used to illustrate the model's features. Although developed specifically for New York City, the model can be applied to other large cities for which a Census Employment Survey has been made. 153 pp.