The judicial selection classification problem is widely recognized but poorly understood. In this note, I identify the classification problem's three interrelated sources: ambiguous theoretical arguments, varying decision rules for categorizing merit selection states, and not accounting for interim selections in mixed systems. To demonstrate threats to inference posed by the classification problem, I replicate a study on opinion writing productivity in state supreme courts. I also offer straightforward suggestions for resolving the classification problem. Eliminating the classification problem will help ensure that inferences are comparable across studies with respect to the consequences of institutional design choices concerning state judicial selection mechanisms.
