Excess Returns Podcast Summary
Episode Title: He Invented the 4% Rule | Bill Bengen on Why He Now Thinks 5% Works
Date: November 12, 2025
Guest: Bill Bengen
Hosts: Matt Zigler, Justin Carbonneau, and (occasionally unidentified co-hosts)
Overview:
This episode features Bill Bengen, creator of the famous "4% Rule" for retirement withdrawals, discussing his groundbreaking research, how it’s evolved over the decades, and why he now argues that retirees can potentially use a higher withdrawal rate—up to 4.7% or even 5% in some scenarios. The conversation delves into the original logic and assumptions of the 4% rule, updates based on new research into asset allocation, longevity, inflation, sequence of returns, and the personal side of enjoying retirement spending.
Main Discussion Points and Insights
The Origin and Evolution of the 4% Rule
Updating the Rule: Toward 4.7% or 5% Withdrawals
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Portfolio Diversification & Asset Allocation
- Early research assumed a stock allocation of 55%. Bengen now advocates for 65% equities to better support higher withdrawal rates.
- “Every time I went to a more diversified portfolio, it increased the withdrawal rate. The last time it went from 4.5 to 4.7%.” (13:59)
- More diversification, including small and mid-cap stocks, further improves withdrawal success rates.
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Role of Inflation and Market Valuations
- The two key variables are inflation and equity valuations (e.g., CAPE ratio).
- Placing inflation first in the analysis clarified the real danger: “Once I put inflation first and put stock market valuation second, everything flowed.” (13:01)
- High inflation is more damaging than market returns: “[Of the two], inflation is most painful because you’re probably stuck with whatever increases you make in your draw rates.” (10:16)
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Adapting for Longevity and “FIRE”
- Extended retirement periods (due to increasing longevity or early retirement movements like FIRE) require only a modest reduction in withdrawal rates, which bottom at about 4.1% for time horizons of up to 100 years. (15:48)
Advanced Withdrawal Strategies
Practical Applications & “Playbook” for Retirees
Notable Quotes and Memorable Moments
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On Retirement Spending:
“People need encouragement to do so [spend money]. It’s pretty clear … if you spend all those years saving money and sacrificing, you should enjoy it.” — Bill Bengen (06:00)
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On Sequence Risk and U-Shape Glide Path:
“If you encounter a major bear market around your retirement and you have lower exposure stocks, you’re not going to get hurt as bad … eventually they run their course and are over, and then you can just pile money basically into a market which is going up.” — Bill Bengen (17:31)
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On the Success and Responsibility of the 4% Rule:
“I feel a little bit like Monk in the TV show … there is a sense of responsibility, of place on my shoulders to get my stuff right, you know, because a lot of people will be reading it and acting often.” — Bill Bengen (37:12)
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On Life Priorities:
“If I’ve learned anything on this journey, you need family, friends, and a passionate interest in something to fully enjoy life. Cultivate all three, and they will not fail you. … If I was to write that paragraph today, I would probably add health.” — Bill Bengen (38:01, 38:48)
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On Bear Markets and Withdrawal Rates:
“If you’re in retirement and you’re tracking your plan and you run into a bear market … bear markets come and go … unless it’s a really extremely deep bear market, you’ll probably be okay. And you’ll find a good recovery on the other side will bring your plan back into alignment.” (39:46)
Important Timestamps
- [00:57] – Bengen introduces his search for the “worst case scenario” and the origin story of the 4% rule.
- [04:36] – Clarifying the key assumptions and misunderstandings of the 4% rule.
- [10:16] – Why inflation is even more damaging than severe market declines.
- [13:01] – How inflation and stock valuations interact to affect withdrawal rates.
- [15:48] – Implications of increased longevity and FIRE movement on sustainable withdrawal rates.
- [17:31] – Explanation of the counterintuitive U-shaped equity glide path.
- [22:52] – Bengen’s perspective on cash buckets and weathering bear markets.
- [23:34] – Commentary on dynamic withdrawal strategies.
- [25:40] – How Bengen personally updated his own withdrawal strategy to 5%, and why caution still matters.
- [30:11] – Key chart: Safe withdrawal rate vs. asset allocation.
- [32:18] – Walkthrough of Bengen’s new planning “playbook”—the “eight elements.”
- [34:26] – Practical advice for retirees with sufficient portfolio size covering most needs.
- [38:01] – Life philosophy: The importance of family, friends, passion, and health.
Conclusion
Bill Bengen’s appearance on Excess Returns offers both a historical deep-dive and forward-looking update on the legendary 4% rule. He makes a strong case that current retirees, with appropriate diversification (particularly up to 65% in equities), could safely withdraw closer to 4.7% or even 5% under many scenarios—though dynamic adjustment, personal circumstances, and humility in the face of market uncertainty remain keystones.
Bengen’s work is characterized not only by rigorous research but also by practical, human empathy—reminding listeners to spend and enjoy their savings, to adjust for longevity, and to prioritize what matters most in life. His updated book, "A Richer Retirement," provides actionable tools for customizing withdrawal strategies, making it a valuable resource for anyone planning their financial future.
Guest’s Book:
A Richer Retirement: Supercharging the 4% Rule to Spend More and Enjoy More — Available at major online booksellers.
Learn more:
- Bill Bengen’s website: https://bengenfs.com
- Excess Returns Network: https://excessreturnspod.com