A Directional Distance Function Approach to Identifying the Input/Output Status of Medical Residents

The application of the human capital theory, the production theory, and the comparison of costs between teaching and non-teaching hospitals all point to the difficulties in identifying whether medical residents should be considered as inputs or outputs. We add to the debate by using a data-driven parametric approach based on the directional technology distance function to determine the status of medical residents. Using the American Hospital Association data from 1994 to 2010 we show that residents are inputs in all rural and in public non-teaching hospitals, but outputs in urban-area teaching not-for-profit hospitals. We also demonstrate that the status of residents is related to the case-mix index and that it can sometimes vary with hospital size.