America's TFR is 1.67. I wanted to understand what it would actually take to get back to replacement (2.1), so I built a simulator where you can stack policies and see the projected effects. Every policy has cited effect sizes (Cohen, Milligan, Raute, etc.) with confidence levels. You can click any policy title to see the methodology and sources. The model includes:

Fiscal tracking (policy costs, deficit impact, GDP effects) Diminishing returns when stacking similar interventions Immigration with selection mechanisms and generational convergence Tax increases and entitlement reform as funding options (with growth drag) A few "illiberal" policies for analytical completeness

The honest answer seems to be: it's really hard. Most realistic packages get you to ~1.9-2.0 at enormous cost, and that's assuming the effect estimates transfer to the US context (they might not). Built with vanilla JS. Feedback welcome - especially on the methodology or effect estimates I got wrong.