To most people macroeconomic theories are of interest because of the policies for which they provide support Thus, Keynesian macroeconomic theory became popular in large part because it was seen as providing a theoretical underpinning for activist monetary and fiscal policy. Similarly, New Classical macroeconomic theory became popular because it became associated with supply side and laissez-faire macro policy.
These associations between policies and theories are, in many ways, dubious. Most theories are multifaceted and, depending on how they are interpreted, can be used to support a wide variety of policies. For example, many Classical economists, including Keynes, supported activist monetary and fiscal policy – in Keynes's case long before he presented the ideas in The General Theory; in The General Theory he never mentions monetary or fiscal policy. There, he talks about socializing investment.
This need to be associated with a particular policy to gain widespread recognition presents a problem for Post Walrasian theory since a central tenet of Post Walrasian theory is that the aggregate economy is so complex that, by themselves, theoretical notions only suggest broad policy rules, not specific mechanistic rules. There is no one set of policies to which Post Walrasian theory leads. In the Post Walrasian approach, policymaking is an art, not a science.
Policy implications of the Post Walrasian view
While there is no specific policy to which the Post Walrasian view of the economy leads, it, nonetheless, has significant policy implications.