Articles / Retirement

Retirement

3 articles

Oct 17, 2026

The Engineering Proof of the 4% Rule: Lyapunov Stability for Retirement Withdrawals

Treat a retirement portfolio as a control system and Lyapunov's stability theorem shows when a withdrawal rate is stable, why 4% works, and why 8% runs out of money half the time.

Sep 24, 2026

Social Security Is Not Disappearing, but Current Law Cuts It About 20 Percent in 2033

Most young workers expect nothing from Social Security. The current-law baseline is not zero, it is a benefit cut of roughly a fifth around 2033, and the

Aug 11, 2026

The 4 Percent Rule, Where It Came From and When It Breaks

The 4 percent rule survived all but one 30-year period in a century of US market history. That single failure tells you exactly where the rule breaks and