The Role of Audits and Enforcement in Taxpayer Noncompliance: Theory.- Evidence Concerning Taxpayer Noncompliance: The Tax Gap.- Evidence Concerning Taxpayer Noncompliance: Enforcement.- Empirical Analysis of Federal Income Tax Audits and Compliance.- The Effect of Audits on Federal Income Tax 1977-1986.- The Effect of Audits and Criminal Investigations on Federal Income Tax 1987-2004.- The Effect of IRS Service Activities on Taxpayer Compliance.-...