A nonpartisan legislative chamber: The influence of the Canadian Senate

Measuring relative legislative influence is notoriously difficult, particularly in bicameral systems where two chambers have similar formal powers. Recent changes to the Canadian legislature offer a unique opportunity to understand how an upper house liberated from party constraints impacts that houses' legislative influence. I leverage an original panel data set matching lobbyist activity to parliamentarian characteristics and responsibilities and, using a difference-in-differences design, compare Members of Parliament to Senators, both independent and partisan. I find that independent Senators receive disproportionately more attention from lobbyists both after the changes and as the independent composition of the Senate grows. This article offers a time-variant measure by which perceived influence can be evaluated and contributes to the extant literature on intercameral relationships, partisanship, the legislative process, and party discipline and cohesion.