Efficiency measurement has been one of the most extensively explored areas of health services research over the past two decades. Despite this attention, few studies have examined whether a providers efficiency varies on a monthly, quarterly or other, sub-annual basis. This paper presents an empirical study that looks for evidence of seasonal inefficiency. Using a quarterly panel of general, acute-care hospitals from Washington State, we find that hospital efficiency does vary over time; however, the nature of this dynamic inefficiency depends on the type of efficiency being measured. Our results suggest that technical and cost efficiency vary by quarter. Allocative and scale efficiency also vary on a quarterly basis, but only if the data are jointly... |