What motivates MPs to serve on oversight-focused select committees? This study investigates assignments in British House of Commons select committees during 2005-15. We developed a unique dataset tracking committee placements across two parliaments.

Data & Methods:

* Original assignment records from the 2005–10 and 2010–15 Parliaments.

* Surveys capturing MPs' long-term policy interests.

* Analysis using logistic regression models comparing partisan vs. informational predictions.

Key Finding:

Our analysis reveals that MPs' persistent policy interests are a dominant driver behind select committee assignments – far more influential than partisan considerations.

This result challenges the expectation that party loyalty would dictate these placements and suggests Wright reforms have reinforced this non-partisan assignment mechanism. By demonstrating how long-standing legislative concerns shape committee memberships, our findings highlight the informational logic underlying British parliamentary oversight politics.