Why more doctors may not mean more essential-specialty physicians

Abstract Purpose Korea is expanding medical school admissions on the assumption that a larger physician pool will relieve shortages in essential specialties. This article argues that the crisis is primarily one of allocation rather than absolute physician numbers, and asks whether increasing total supply will increase the number of physicians actively practicing in essential specialties. Current concepts A physician’s field of practice is not fixed at licensure. Published reanalyses of claims data indicate that many board-certified specialists in primary care display a practice department other than the specialty they trained in. As a thought experiment, entry into and retention in an essential specialty can be framed as an expected-value comparison weighing a gain term (career success and net return) against a cost term (litigation and licensing risk). This framing makes explicit which term policy affects; the parameter values are stated assumptions, not empirical estimates. Under a fixed insurance budget, added supply dilutes the return term without increasing reimbursed essential work, whereas the cost term is set by the medico-legal environment rather than supply. Displaced specialists may accumulate in substitutable aesthetic and general-practice markets, while non-substitutable essential capacity remains unfilled. Discussion and conclusion Essential-specialty participation may track specialty-specific incentives more closely than physician headcount. If so, expanding admissions while expected value remains low would not necessarily increase the essential-specialty workforce, whereas restoring returns and lowering medico-legal costs could create conditions for re-entry. Quota adjustment alone may be an incomplete policy lever. This is a conceptual, hypothesis-generating argument requiring examination with longitudinal data.