Expert analysis on historical simulation, withdrawal strategies, and financial independence planning
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 …
The retirement date itself drives roughly 75% of outcome variance across 97 historical cohorts, more than withdrawal rate, allocation, or guardrails combined. A two-year flexibility …
Historical 90% and Monte Carlo 90% Are Not the Same Number Even when both say 90% success and displayed the same way, they do not …
You ran a retirement simulation and got two results. The historical backtest says 98.9% success. The Monte Carlo says 90.5%. Which one is right? Both. …
Discover why two retirees with identical $1 million portfolios can have vastly different outcomes. Historical analysis of sequence-of-returns risk explained.
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Same markets, opposite fortunes. Why 1969 made savers rich and retirees poor while 1949 did the reverse.
Every retirement calculator, every "how much should I save" article, every financial planning spreadsheet uses the same formula. It's elegant. It's simple. And it hides …
Does American advice work for UK savers? In this post I want to look at how the 3% saving strategy performs, historically, in the UK …
We use Bellavia Analytics to calculate how much we need to save on a yearly basis for 30 years in order to have a very …
When it comes to savings, when you start is just as important as how much you contribute.
Imagine it's January 1936 and you've just retired with £1,000,000, a fortune. Suppose you follow today's "sensible" advice: withdraw 4% annually from your balanced 60/40 …
The 1966 retiree could safely withdraw 3.9% annually (adjusting for inflation). The 1982 retiree could safely withdraw 11.8%, a full three times more spending power …
When planning for retirement, small differences in withdrawal rates can have dramatic impacts on portfolio longevity. This analysis explores what happens when you increase your …
1966 was worse than 1929. We tested how the same $1M portfolio performed starting in four of history's riskiest retirement years. Two failed completely. Two …
After years analyzing financial models, I searched for retirement planning tools. What I found was disappointing: oversimplified calculators or black boxes that said "trust us." …
Type "how long will $1 million last in retirement" into Google. You'll get a dozen articles all saying the same thing: "it depends" or "25-40 …
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 …
A step-by-step guide to accessing and formatting the Jordà-Schularick-Taylor Macrohistory Database for use in Bellavia's retirement planning simulations. This comprehensive dataset spans 1870-2020 and includes …
Before you can stress-test your retirement plan against 100+ years of market history, you need to understand what you're actually testing. This guide breaks down …