Advocacy versus Certainty: The Dynamics of Committee Jurisdiction Concentration

I present an aggregate-level theory paralleling the theory of market competition to explain the dynamics of committee jurisdiction concentration. The theory states that organized issue constituents and the larger voting public, respectively, make private (i.e., advocacy) and collective (i.e., certainty) demands for policy benefits supplied by committees. I hypothesize that the levels of these competing demands drive two activities changing committee jurisdiction concentrations: "nonlegislative" and "legislative" jurisdiction advances. To test my hypotheses, I use nonlegislative committee hearings and bill referrals over a 15-year period (1979-93) to construct annual, issue-specific Herfindahl indexes measuring nonlegislative and legislative jurisdiction concentrations. I use PAC contributions and issue salience to measure private and collective demands for policy benefits. Using two OLS regression models, I find that both types of demand influence the two jurisdiction advancement activities. Moreover, nonlegislative jurisdiction advances produce a nonconcentrated jurisdictional arrangement, while legislative jurisdiction advances produce a concentrated jurisdictional arrangement.