This article, titled "Docketology, District Courts, and Doctrine," by three Temple law professors, concludes:
"Our analysis supports the view that trial judges employ opinions as briefs to appellate courts, seeking to reduce the professional and personal risks arising from appellate review."
"We argue that judges
believe that individual decisions within cases accompanied by opinions are less likely to be reversed than those without such reasoning. Therefore, judges may write opinions – instead of mere orders – for decisions they believe will be reviewed by a higher court."
"We conclude that drafters of Restatements, treatises, and other qualitative descriptions of the common law remain too wedded to opinions, and ignore the ways in which the dozens of judicial choices in each case, ranging from motions to compel, to partial grants of motions to dismiss, to motions in limine, together create important, unseen, limits and glosses on doctrine."
Thus, I heard stories of "the law of Buchanan County."
The article is an interesting but complicated analysis of opinion by federal district judges, and worth checking out.