A principal challenge in small area population estimation is to find adequate data and appropriate methods for estimating domestic migration. Tax return data collected by the Internal Revenue Service (IRS) are employed by the US Bureau of the Census to conduct population estimates at the county level.  Since the IRS data are not available for cities/towns, the Bureau has developed the housing-unit method to estimate population at the sub-county level.  However, this method requires a vast amount of information that is not always easy to acquire. Data provided by various agencies are often found to be incomplete and inaccurate. This method is especially problematic when applied to areas with a large population of minorities, immigrants, and college students. Moreover, the method is too complex to manage and too costly in time and financial resources when collecting and analyzing data on an annual basis. In preparing the 1991-97 population estimates for Massachusetts at the state and the sub-county levels, I have developed the city/town ratio method, attempting to address the issues mentioned above and to propose a new strategy for producing local population estimates.