How many dimensions are there in Congressional roll-call votes? What do dimensions tell us about Congressional politics? Poole and Rosenthal have found one or a very few dimensions. Earlier work has identified problems with Poole and Rosenthal's dimensional fitting method. This paper finds...

Dimensional studies of Congressional voting have found a single dominant "ideological" dimension, while regression estimates find that constituency variables and party are dominant. Koford (1989b) recalibrated the dimensional studies, and found that several dimensions are important. This study...