Rodrik on ideas and public choice theory
There are three ways in which ideas shape interests. First, ideas determine how political elites define themselves and the objectives they pursue – money, honor, status, longevity in power, or simply a place in history. These questions of identity are central to how they choose to act.
Second, ideas determine political actors’ views about how the world works. Powerful business interests will lobby for different policies when they believe that fiscal stimulus yields only inflation than when they believe that it generates higher aggregate demand. Revenue hungry governments will impose a lower tax when they think that it can be evaded than when they think that it cannot.
Most important from the perspective of policy analysis, ideas determine the strategies that political actors believe they can pursue. For example, one way for elites to remain in power is to suppress all economic activity. But another is to encourage economic development while diversifying their own economic base, establishing coalitions, fostering state-directed industrialization, or pursuing a variety of other strategies limited only by the elites’ imagination. Expand the range of feasible strategies (which is what good policy design and leadership do), and you radically change behavior and outcomes.