This chapter describes the Enterprise Zone (EZ) Fiscal Impact Project conducted in 2003 by the Of?ce of Fiscal and Management Analysis (OFMA), Indiana Legislative Services Agency (LSA). The focus of this project was to better inform policy analysts and policy-makers about the extent and nature of business activity within Indiana’s 29 EZs. The most important outcomes of the project were the generation of digitized maps of the EZs and the geocoding of data from the Quarterly Census of Employment and Wages (also referred to as ES-202 data) to the EZs. The geocoding process yielded a census of business establishments in the EZs, and a dataset reporting employment levels, wage levels, and industry classi?cation information for each business identi?ed in the EZs. The project failed to yield much-needed information on sales receipts, income, and investment expenditures by EZ businesses. Researchers conducted a survey of EZ businesses to obtain this information, but the survey failed to yield suf?cient samples to draw conclusions about EZ businesses. In addition, geocoding of tax return data was considered, but researchers determined the geocoded tax return data would not yield valid and reliable information about EZ businesses. This project has provided valuable descriptive information for EZ administrators and was utilized by OFMA staff to estimate ?scal impacts of proposed EZ tax incentives for the Indiana legislature. The case also demonstrates how analysts can utilize GIS and available data sources to create new demographic and socio-economic databases for localized and idiosyncratic geographic areas. Nevertheless, the case also suggests that widespread geocoding of existing databases containing geographic information may not lead to a GIS that validly re?ects phenomenon in such areas. Thus, researchers must exercise caution in geocoding and utilizing the resulting databases for research and analysis.