Judges, Justice, and Public Choice

From Dennis Mueller's textbook Public Choice III:

The public choice literature's approach to the problem of defining the objectives of the judiciary has been to assume it away -- that is, to assume an objective for the judiciary without defending this assumption, and then proceed to analyze the consequences of this assumption for legislative outcomes.  Although this approach can be defended as a first step in integrating the judiciary into models of legislative behavior, it obviously makes such models of limited use, unless we can determine more concretely what it is that judges maximize and why they do so.  The question of the motivation of judges in an independent judiciary remains largely an empty black box in the public choice literature.  (Mueller, p. 401)

It's just common-sense that the motivation of judges can't be understood without reference to the raison d'etre of judges, namely, justice.  Economists have a bad habit of assuming "rational agents" whose behavior is unaffected by ethical values.  Sometimes, e.g., in most business or consumer decisions, this is innocuous.  But when economists engage in "imperialism" and study areas outside the strict market sphere, it would be useful to introduce stylized ethical elements into behavior, e.g., altruism coefficients, or side-constraints against lying or stealing.  Instead, economists have an unfortunate habit of adopting a pose of knowing cynicism, as if they have some secret knowledge that everyone is really self-interested and the rest of the world is naive.

To have a sensible theory of the behavior of judges, you have to assume-- and somehow work it into a model-- that at least one of the things that motivates them is justice.