Statistics of income

The Corporate Source Book is created annually from a stratified sample of the 1.5 to 1.8 million corporation income tax returns filed. The sample is stratified on the basis of total assets, net income or deficit, minor industry codes, and type of return. The records are arranged by minor industry codes, asset size class, and by net income/no net income. Sample rates range from 2 to 100 percent, increasing with asset size. There are two records (one with net income and one without net income) for each of the asset size classes, for each of the minor industry codes. The more than 6,000 records represent the averages for the 110,000 to 150,000 corporate income tax returns sampled annually. Since this file represents a sample of all returns and the data elements in the record represent averages for that industry and asset size class, users doing research based upon these records should review the IRS materials pertaining to the sampling variability which are published annually in Statistics of Income: Corporate Source Book. Column locations and variable descriptions are contained in the multilithed documentation.