The Senate Budget Committee has published the Congressional Research Service's 931-page report, Tax Expenditures: Compendium of Background Material on Individual Provisions, 110th Cong., 2d Sess., Print #667 (Dec. 2008):

[E]ach entry includes an estimate of each tax expenditure’s revenue cost, its legal authorization, a description of the tax provision and its impact, the rationale at the time of adoption, an assessment, and bibliographic citations. The impact section includes quantitative data on the distribution of tax expenditures across income classes where such data are relevant and available. The rationale section contains some detail about the historical development of each provision. The assessment section summarizes major issues surrounding each tax expenditure.