This paper is the first of a series that summarizes and analyzes these policies and proposals. The series has two broad goals: to describe, interpret, and assess what has happened; and to examine the consequences of making the tax cuts permanent. This paper provides background information intended to help frame the issues analyzed in subsequent papers. Those papers will examine the distributional effects; tax cuts and fiscal policy; the effects on long-term growth; the effects as a short-term stimulus; the effects on government spending; and the extent to which the tax cuts serve as an effective prelude to fundamental tax reform.