The authors are Donald Marron and Eric Toder. The abstract:

The federal government is larger than conventional budget measures suggest. Many tax preferences are effectively spending programs. Adding these preferences to federal outlays and receipts makes the government appear about 4 percent of GDP larger. The 1986 tax reform cut these benefits, but they have since rebounded to a larger share of GDP than before. Using this broader measure of government size, many base-broadening reforms viewed as tax increases would be reclassified as spending cuts. Raising marginal tax rates would be recorded as a tax increase and a spending increase because it would boost the value of many tax preferences.

Full paper here.