US MONIAC simulator
Why I built it
MONIAC grew out of my effort to teach myself basic economics through an interactive visual model. Turning an unfamiliar system into controls, flows, and explanations is a way for me to learn — and to practice making complex ideas easier to understand.
My contribution is software engineering, interface design, and interactive communication, not economics expertise. This is a learning project, not a claim to be an economist.
Problem
An animated economic model can look convincing even when its equations contradict its explanations. This project explores how to make an educational simulation engaging without disguising its limitations.
Approach
The dashboard separates pure simulation functions from React state, display formatting, and canvas rendering. Policy changes update an existing animation engine rather than restarting it. A shared token system supports dark and light themes; pause controls and reduced-motion preferences stop particle animation.
The model includes interest-sensitive demand, lagged price pressure and labor slack, and explicit supply and credit shocks. Thirteen historical experiments introduce source-linked context before applying illustrative settings. Each starts from the same neutral baseline so that runs can be compared.
What the numbers mean
Outputs are normalized indices, not GDP dollars, measured inflation, or forecasts. The coefficients are transparent teaching assumptions, not fitted estimates. The model does not reconstruct historical events, and its flow diagram is not a balanced national-accounts system.
Correcting the prototype meant more than reversing a sign: the interface also had to stop implying that arbitrary normalized values were real economic measurements. Scenario explanations distinguish what happened historically from what this small model can demonstrate.
Engineering evidence
The implementation includes Vitest coverage for model behavior, deterministic output, state lifecycle, display derivation, and animation cleanup. Playwright coverage exercises scenario application, keyboard dismissal, theme switching, mobile layout, and automated accessibility scans. The modal uses a native dialog and applies policy only after its exit transition.
This is an educational portfolio project, not an economic research or forecasting product. No rendering-performance benchmark or completed manual accessibility certification is claimed.