Stock-and-flow model of Pakistan's doctor pipeline (year 0 = 2025). Calibrated to: 385,259 registered doctors (PMDC, via Nukta, Feb 2026); 22,000 new registrations a year (PMDC, via The News, Feb 2026); about 4,000 doctors emigrating in 2025 (Gallup Pakistan, from Bureau of Emigration data); 12.5% of emigrants return (PIDE KB 102 says 10-15%). Loop gain (0.20) and shock size (2 points for 2 years) are assumptions. Reinforcing loop: fewer doctors raises workplace strain, which raises emigration. Intervention (Category A, leverage point 7): a retention package cuts the loop gain from 0.20 to 0.05. Retention Policy slider: 0 = before, 1 = after.
