Why More Doctors May Not Mean More Essential-Specialty Physicians

BackgroundI present an illustrative conceptual model of how economic and legal disincentives may drive specialty and practice-setting misallocation in South Korean essential medicine, alongside--not instead of--aggregate workforce constraints, examined through the "Vital 5" specialties (Internal Medicine, General Surgery, Obstetrics & Gynecology, Pediatrics, and Cardiothoracic Surgery). MethodsI built two models: a Human-Capital Misallocation Cost model estimating resources lost when specialists work outside their training, and an Expected Value (E(V)) model of entry into essential fields incorporating Net Return (R_net), Probability of Lawsuit during a practicing physicians lifetime (P_suit), and Cost of Risk (C_risk). All parameters are stated assumptions with sensitivity analyses. A national replacement-cost equivalent was derived from emergency-system expenditure per resident vacancy in the 2024 crisis and a mismatch rate taken directly from national data. ResultsNational data show a high proportion of cardiothoracic surgeons practicing outside their major field. Under the stated assumptions, expanding admissions dilutes R_net and, through undertraining, raises P_suit; E(V) then declines and falls below zero only when litigation exposure is assumed to rise, remaining positive when it is held constant. The reversal therefore depends on the assumed expansion-litigation link, not on income dilution alone. ConclusionI propose, as a model-derived hypothesis, a "Paradox of Expansion": expanding quotas without addressing compensation and legal risk may reduce, rather than increase, active specialists in selected essential fields. I compare no alternative policies and identify no optimal policy; I argue only that quota expansion alone is unlikely to improve essential-specialty retention unless reimbursement and medico-legal risk are addressed concurrently.