The definition of regime has been criticized as being expansive to the point
of vagueness (Strange, 1982). An unfortunate consequence is that an inordinate
amount of effort has been expended in arguing about whether or not there is an
effective regime in a particular area. The corresponding virtue is that this broad
definition allows for a broader view of governance possibilities than is
suggested by the narrower concern with formal institutions. The various
categories in the definition also point towards a greater level of specificity than
is often achieved by more ethereal discussions of ordering principles. Finally,
the breadth of the definition leaves room for a plurality of approaches - liberal
as well as realist, rationalist as well as constructivist. This has provided some
unity to the field despite the diversity of approaches sometimes employed.
Regime ‘theory’ is confusing insofar as it refers to a body of literature
including a wide range of different approaches and theories. Nevertheless, the
most substantial vein of regime theory relies on rational choice understandings
of state behavior, where states are viewed as unified, self-interested actors
(Hasenclever, Mayer and Rittberger, 1997). We emphasize rationalist
approaches for this reason and because they are closest to the law and
economics tradition