DW-NOMINATE scores for the U.S. Congress are widely used measures of legislators' ideological locations over time. These scores have been used in a large number of studies in political science and closely related fields. In this paper, we extend the work of Lewis and Poole (2004) on the...

DW-NOMINATE scores for the U.S. Congress are widely used measures of legislators' ideological locations over time. These scores have been used in a large number of studies in political science and closely related fields. In this paper we extend the work of Lewis and Poole (2004) on the...

Empirical models of spatial voting allow legislators' locations in an abstract policy or ideological space to be inferred from their roll call votes. Over the past 25 years, these models have provided new insights about the US Congress and legislative behavior more generally (see, for example,...

In many many places, the political parties and political contests seem to array themselves along a single dimension. If you look at their programs in detail it always turns out that it's much more complicated than that. But it would appear that in the minds of the voters they are literally...