ARE LEGISLATORS IDEOLOGUES OR THE AGENTS OF CONSTITUENTS

Legislatures often make important economic decisions. A decade ago eco nomists viewed each legislator as the agent, if not of the median vote r, of some pivotal voter in a party constituency. Therefore, the votin g decision of a legislator could readily he predicted if one could mea sure the preferences of the relevant pivotal voter. Models where inter ests on specific issues can be simply linked to votes on the same issu es are questionable, however, since votes will be traded across issues ; Political parties are one important vehicle for organizing such trad es. A simple empirical test for the United States Senate, however, cle arly rejects the notion that the representative is the agent of the me dian voter or a local party constituency, even if vote trades are allo wed. Thus, there is ample opportunity for politicians, even under reel ection constraints, to either voice their own ideology sr that of idio syncratic support coalitions. The relevant theory and empirical eviden ce is summarized, and some validating tests for European parliaments a re suggested.