Retirement Planning Insights

Expert analysis on historical simulation, withdrawal strategies, and financial independence planning

GK Guardrails Explained: How the 2006 Decision Rules Actually Work

GK Guardrails Explained: How the 2006 Decision Rules Actually Work

Compare Bellavia's two guardrail withdrawal strategies — parametric (user-set 3%/5% bands) and canonical Guyton-Klinger 2006 (four fixed rules) — across 91 historical cohorts. Includes a …

18 min
The 4% Rule Is Wrong: What the Creator Now Recommends

The 4% Rule Is Wrong: What the Creator Now Recommends

For 30 years, retirees have trusted the 4% rule to make their savings last. But William Bengen, the financial planner who invented it, later said …

12 min