Sunsets cause rent seeking, revenue loss, and uncertainty.
Rebecca M. Kysar 6, a professor at Fordham University School of Law, 3-2-2006, Georgia Law Review, "The Sun Also Rises: The Political Economy of Sunset Provisions in the Tax Code," https://papers.ssrn.com/sol3/papers.cfm?abstract_id=887388 //AS
The story of sunset provisions in the code chronicles how these “good government” reform devices are, in actuality, rent-extracting mechanisms that encourage budgetary sophistry. First, sunset provisions evade political constraints in the budget process whose purpose is to safeguard against congressional over-spending. The sunset provisions of the extenders and, much more dramatically, the 2001 and 2003 tax cuts were enacted to underestimate the revenue losses of the provisions to which they apply. Second, sunset provisions further reduce the reliability of revenue loss estimates. Moreover, the existence of sunset provisions in the recent tax acts has created political conditions under which re-enactment of important budget rules, such as the PAYGO provisions, is very unlikely while sunset repeal is on the table.
Third, sunset provisions threaten the continuance of tax benefits and thus allow legislators more possibilities to extract financial and electoral contributions from the recipients of those benefits. Therefore, politicians have an incentive to perpetually endanger provisions that provide rent-extracting opportunities. The case of the tax extenders—in which many popular provisions, such as the R&D credit, were never made permanent—supports this hypothesis. Both EGTRRA and JGTRRA contain core provisions advantaging a narrow group of individuals and entities. These groups vie for the extension of benefits in their interest while legislators, by collecting rents, make the most out of the disagreement over the permanent enactment of the tax cuts.