This research aims to evaluate the behavior of senators in roll calls from 1989 to 2010. To the extent that the Senate is endowed with extensive powers, is composed by members with a long political history and it is the federative house, this work will verify whether presidential powers and party leaders are able to mold the preference structures of individual senators. In other words, it verifies which and how many dimensions are necessary to represent at least fairly the preferences of senators. The W-NOMINATE will be the technique used for this purpose.
From Maurício Yoshida Izumi.