Some of the information in this post may be out of date. Please speak to a librarian for more up to date information.
Most people are unaware of an office within the IRS called Statistical Information Services (SIS), an office with a mandate to facilitate the dissemination of data collected by the Statistics of Income (SOI) program. SOI collects, tabulates and publishes IRS data used “to analyze tax policy, project tax revenues, and estimate the overall impact of tax law changes and their effects on tax collections”. How tax data is captured, sampled, weighted and analyzed is explained on a page titled The Work SOI Does. Data is aggregated and includes, but is not limit to, data on:
- individual tax studies (sources of income, exemptions, deductions, taxable income, etc.)
- sole proprietorships by industry, business receipts, deductions, and net income
- tax analysis of high income tax returns
- corporate (including S-corporations) taxation classified by industries, accounting periods, and size of assets, receipts, and income taxes after credits
- aspects of investment and activity in the United States by foreign persons
Various products (some free and some for a minimal fee) are available through the SOI site. One of the more popular publications is the SOI Bulletin, a quarterly newsletter with featured articles from analysts studying a particular tax topic. The spring issues (e.g., Spring 2012) of this newsletter includes selected historical and other data tables also available at www.irs.gov/taxstats. And index of SOI Bulletin articles is available by topic. Additional products include individual income tax zip code data available in Excel tables for 2002, 2004, 2005, 2006 and 2007 that can be purchased for $25 per state or $500 for the entire United States. County income data is available for tax years 1989 through 2006 for $50 per year for the entire United States and $10 per year per state. The page SOI Projects, Contacts, and Public Release Information gives contact information for the Statistical Information Services office and the name of each analyst assigned to a particular project (e.g., corporation income tax returns or estate tax returns).