Summary: The Internal Revenue Service (IRS) plans to spend $2.9 billion to modernize its information systems. This report reviews the latest draft of IRS' Investment Decision Management Business Case Procedure, which guides the agency's information technology (IT) investments. GAO discusses changes to the guidance that would ensure that the economic analyses in IRS business cases are consistent with commonly accepted principles. IRS' draft guidance on business case documentation represents an important step toward ensuring that IRS management has relevant information on which to base its critical IT investment decisions. However, some aspects of IRS' guidance are inconsistent with commonly held principles of public sector cost-benefit analysis. Most important, the guidance does not require the computation of a comprehensive social net present value (NPV)--the standard for deciding whether a government investment can be justified on economic grounds. The two partial NPV computations that IRS' guidance requires are inappropriate because they do not incorporate the proper values for all relevant benefits and costs for investment projects with significant effects outside of IRS. In addition, IRS' two NPV's are not additive, so even if all benefits and costs were properly valued, decision makers would be unable to determine the overall net value of an investment.
