Tax deductions, credits and exclusions cost the federal government approximately $1.1 trillion dollars in FY 2013. While these expenditures can help provide incentives and spur growth in industries from manufacturing to education, the individual tax breaks’ effects are rarely subject to rigorous evaluation after the breaks are codified. To aid in this evaluation and other analysis around the tax code, the non-profit federal budget transparency group National Priorities Project has assembled the data on tax expenditures going back to 1974.
The data set, which is available in its complete form for the first time, was cobbled together from a range of sources and normalized. It also includes derived statistics for each year such as tax expenditure as a percentage of GDP, and the amount of tax expenditure that benefits corporations versus individuals.