Horizontal federalism: Exploring interstate interactions

Abstract

States interact with each other in ways that have consequences for the American federal system. The focus of this article is interstate cooperation-multistate efforts to pursue shared agendas or solve common problems. Three mechanisms are examined: interstate compacts, multistate legal actions, and uniform state laws. The data show that during the 1990s, states engaged in all of these behaviors but at differing rates. Furthermore, the explanations for interstate cooperation vary. Government capability proved to be an important explanation but in opposite ways: more capable states join multistate legal actions, and less capable states adopt uniform state laws. The implications for the federal system are considerable: effective interstate cooperation may offer an alternative to federal legislation. For state officials, the implications are equally significant: interstate cooperation spawns administrative networks that fall outside traditional structures.