The most recent explanations for the existence of committee systems in legislative chambers have posited that committees are the agents of one of three very different principal actors: (1) individual members (distributive theory), (2) the full chamber (informational theory), or (3) the major political party (partisan theory). In addition to defining and operationalizing the concept of institutional committee system autonomy, I put forth and test several hypotheses linking these three explanations to committee system autonomy. In the end, the results show empirical support for the informational theory over the distributive and partisan theories.