Empirical legal scholars have traditionally modeled trial court judicial opinion writing by assuming that judges act rationally, seeking to maximize their influence by writing opinions in politically important cases. Support for this hypothesis has reviewed published trial court opinions, finding that civil rights and other "hot" topics are more likely to be explained than purportedly ordinary legal problems involved in resolving social security and commercial law cases. This orthodoxy comforts consumers of legal opinions, because it suggests that they are largely representative of judicial work. To test such views, we collected data from a thousand cases in four different jurisdictions. We recorded information about every judicial action over each case's life, ranging the demographic characteristics, workload, and experience of the writing judge; to information about the case, including its jurisdictional basis, complexity, attorney characteristics, and motivating legal theory; to information about the individual orders themselves, including the relevant procedural posture and the winning party. This approach permits a significantly more fine-grained look at how courts give meaning to legal rights than had been previously available. Descriptively, we find that opinions are rare events in the litigation process: only 3% of all orders are explained in opinions, and only 17% of orders applying facts to law are similarly reasoned. Using a hierarchical linear model, we find that judges do not write opinions to curry favor with the public or with powerful audiences, nor do they write more when they are less experienced, seeking to advance their careers, or in more interesting case types. Instead, opinion writing is significantly affected by procedure: we predict that judges are three times more likely to write an opinion on a summary judgment motion than a discovery motion, all else held equal. Judges similarly write more in cases that are later appealed, and in commercial cases. Finally, jurisdictional culture is very important. These findings challenge conventional views of trial court opinion writing, and suggest the need for further research to test a behavioral model for judges' behavior
