Unpacking the unknown: a method for identifying status quo distributions

摘要

Assumptions and implications regarding status quo locations are a common feature of theories of legislative politics. Yet challenges with measuring status quo locations have frustrated scholars for decades. This article introduces a method for measuring status quo distributions within individual, majority-rule legislatures. In particular, our identification strategy is grounded in the simple assumptions that bill sponsors are purposive, legislators vote for the policy alternative nearest their ideal point, and the chamber median is decisive. We derive analytically the probability that a legislator votes with the winning coalition as a function of her ideal point, the distribution of status quo locations, and the distribution of sponsor ideal points. We then introduce an optimization program that allows researchers to back out status quo distributions given the other, readily available inputs used in the analytical solution. We demonstrate its implementation by estimating the status quo distributions for US Houses of Representatives between 2005 and 2016.