In Ron Collins’s latest installment with Judge Posner, we gain an insight about why he does not issue per curiam opinions.

I stopped issuing per curiam opinions some time ago; it didn’t seem to me that “per curiam” was sending a useful signal; I couldn’t see the point of concealing authorship. West asks each judge to list his per curiams, and they are then included in the annual volume of a judge’s opinions, which West prepares and sends to the judge. So anyone who is interested could find out which per curiams have been mine. 

I agree. I have similar feelings about unpublished opinions.