Agenda setters, responders, or both? Organized interests and Congressional agendas

At what point organized interests become involved in the policy process is a matter of debate for scholars. On one side are the interest groups scholars who argue that groups set the agenda and members of Congress respond; at the other end of the spectrum are Congressionalists who give credit to those with power over the formal agenda and relegate organized interests to a responsive position. The compromise approach promoted by some is that both are involved in a muddied process to shape the agenda. By looking at activity both before and after arrival on the formal agenda, I test to see which comes first---the group, the member, or both? Using three different tests for agenda-setting activity, I discern that both members of Congress and organized interests play a role in agenda-setting, but organized interests play the larger part.