The Paradox of Expansion: Why Increasing Medical School Quotas May Reduce Essential-Specialty Physicians in Korea

Technical Summary: The Paradox of Expansion in Korean Essential Medicine

Problem Statement
The paper addresses the ongoing medical crisis in South Korea, specifically challenging the government's assumption that increasing medical school quotas will naturally resolve shortages in "Vital 5" essential specialties (Internal Medicine, General Surgery, Obstetrics & Gynecology, Pediatrics, and Cardiothoracic Surgery). The author argues that the crisis is not merely a matter of aggregate physician supply but is driven by a distinct mechanism: specialty and practice-setting misallocation. Despite a growing total number of doctors, a significant proportion of trained specialists in essential fields are engaging in "Rational Evasion," migrating to low-risk, non-essential sectors (e.g., aesthetics, general practice) due to unfavorable economic returns and high medico-legal risks. The paper posits that without addressing these structural disincentives, quota expansion may paradoxically reduce the number of active essential specialists.

Methodology
This study employs a conceptual modeling approach rather than empirical causal identification. It utilizes two primary theoretical frameworks:

1. Human-Capital Misallocation Cost Model: This model quantifies the financial resources lost when specialists practice outside their training. It calculates the cost ($C_{misalloc}$) as the sum of public and private education/training investments ($C_{edu} + C_{train}$) multiplied by a mismatch coefficient ($1 - \alpha$), where $\alpha$ represents the degree of alignment between training and actual practice.
2. Expected Value (E(V)) Model: This model simulates the decision-making process for entering essential medicine. It defines the Expected Value as a function of:
   • Net Return ($R_{net}$): Lifetime income adjusted for work intensity and opportunity costs, assumed to dilute under a fixed National Health Insurance budget if the physician headcount increases.
   • Probability of Lawsuit ($P_{suit}$): The lifetime probability of facing legal action, which the model suggests may rise due to undertraining in an expanded cohort.
   • Cost of Risk ($C_{risk}$): The financial and professional cost of litigation, including criminal penalties and license revocation.

The study includes hypothetical case simulations (a Cardiothoracic Surgeon working in varicose vein therapy and a Pediatrician in an aesthetic clinic) to estimate individual misallocation costs. Additionally, it derives a National Misallocation Cost using a replacement-cost equivalent based on the 2024 medical crisis expenditure (3.4 trillion KRW for 10,000 resident vacancies) and applies a mismatch rate derived from national audit data to the "Vital 5" specialist population.

Key Contributions

• The "Paradox of Expansion" Hypothesis: The paper introduces the hypothesis that expanding medical school quotas without concurrent reforms in reimbursement and medico-legal risk may reduce the number of active essential specialists. This occurs because expansion dilutes income ($R_{net}$) and potentially increases litigation risk ($P_{suit}$), causing the Expected Value ($E(V)$) of essential practice to fall below that of alternative, lower-risk markets.
• Quantification of Misallocation: The study provides an illustrative calculation of the economic waste associated with current misallocation, estimating an annual replacement-cost equivalent of approximately 1.7 trillion KRW for the mismatched "Vital 5" specialists alone.
• Distinction Between Supply and Allocation: The author clarifies that the issue is not a lack of total physicians but a failure of the "trickle-down" effect, where supply does not flow to essential fields due to relative unattractiveness driven by risk and compensation structures.

Results

• Current Misallocation: National data reveals that only 18.1% of licensed Cardiothoracic Surgeons practice in their major field, with 81.9% engaged in "Rational Evasion" in non-vital sectors. Similar, though less severe, mismatches exist for General Surgery (52.1%), Obstetrics & Gynecology (38.0%), Pediatrics (24.1%), and Internal Medicine (12.1%).
• Simulation Outcomes:
  • Under a scenario where the medical school quota increases by 2,000 (raising the total to 4,058), the Net Return ($R_{net}$) per physician is assumed to drop to 75% of the baseline due to a fixed insurance pool.
  • If litigation exposure ($P_{suit}$) remains constant, the $E(V)$ remains positive but reduced.
  • However, if the expansion leads to a deterioration in training quality and a subsequent rise in litigation probability (from 0.10 to 0.16), the $E(V)$ for essential medicine turns negative (-0.16).
  • This negative $E(V)$ creates a strong incentive for new specialists to avoid essential fields in favor of aesthetic markets or overseas employment.
• Historical Context: The paper contrasts the current situation with the 1980s, noting that essential specialties were then highly coveted despite a smaller total physician pool. This suggests that relative attractiveness (high $E(V)$), rather than absolute scarcity, drives specialty choice.

Significance and Claims
The paper explicitly states that it does not propose an optimal policy nor does it claim to have empirically identified a causal effect of quota expansion on specialty choice. Instead, it offers a model-derived hypothesis to explain the persistence of the essential-specialty vacuum.

The author argues that headcount is the wrong policy lever. The central claim is that increasing the supply of doctors while $E(V)$ remains negative (due to high risk and low return) will not fill essential fields and may exacerbate the shortage by accelerating the "de-skilling" and exodus of specialists. The paper concludes that structural reforms addressing reimbursement levels and medico-legal risk (e.g., no-fault compensation systems) are necessary preconditions for any quota expansion to be effective. Without these concurrent measures, expanding quotas risks producing a larger workforce that continues to bypass essential care, deepening the vacuum in critical specialties.