AI Summary
5 min read50 Years of Evidence-Based Investing (w/ David Booth)
David Booth co-founded Dimensional Fund Advisors in 1981 in the spare room of his Brooklyn apartment. Today, that firm manages roughly $1 trillion in global assets. In this conversation, Booth draws on over 50 years at the center of evidence-based investing to explain how the science of financial markets was built, why implementation matters more than ideas, and what it really means to make good decisions under uncertainty.
The Data Revolution That Changed Everything
Before the 1960s, there was no research-quality data to test hypotheses about financial markets. That changed when professors Jim Lorie and Lawrence Fisher persuaded Merrill Lynch to fund a data collection on stock and bond returns starting in 1926. As Booth recalls, "This was big data back before people even called it big data."
Armed with that data, researchers at the University of Chicago — including Eugene Fama, Merton Miller, and Myron Scholes — began producing results that challenged everything Wall Street believed. The two key findings: stock markets behave the way we hope they would (about 10% annual returns over long periods), and professional money managers trying to outguess the market consistently underperform once fees are considered.
Continue reading the full summary in the app — free to try.
Read Full Summary →Free • No credit card required
Never miss an episode of The Rational Reminder Podcast
Get every new episode summarized in your inbox — free, ~5 minutes to read.
No spam. Unsubscribe anytime.
What you'll learn
- 1 (00:00) **Episode Introduction** - Ben Felix and Cameron Passmore introduce David Booth, co-founder of Dimensional Fund Advisors, and his new book *Stay Calm*.
- 2 (01:22) **The Shoe Store Lesson** - Booth explains how selling shoes on commission taught him a core business philosophy.
- 3 (03:52) **The Gift of Being an Outsider** - Booth describes how his parents' outsider mindset shaped his understanding of markets.
- 4 (05:54) **Challenging Wall Street with Data** - Booth recounts the early days of challenging established beliefs with empirical evidence.
- 5 (08:06) **The University of Chicago Crucible** - Booth describes the intense, collegial environment that sharpened his research skills.
- 6 (12:21) **The Two Fish and the Data Pioneers** - Booth uses a joke to explain the importance of understanding the environment you're in.
- 7 (15:50) **Indexing vs. Passive Investing** - Booth draws a critical distinction between indexing and a science-based passive approach.
+ Full timestamped outline available in the app
Guests on this episode
Show Notes
In this episode, we welcome back David Booth, Co-Founder of Dimensional Fund Advisors and author of Stay Calm: Learn to Embrace Uncertainty in Investing and Life. David reflects on his remarkable career at the center of the evidence-based investing revolution, from studying under Eugene Fama at the University of Chicago to helping build investment strategies around decades of financial research.
We explore what the data revealed about markets and professional money management, why implementation matters as much as great ideas, and how investors can make better decisions without trying to predict the unpredictable. David also shares his views on trust, financial advice, public versus private markets, human ingenuity, and the meaning of true wealth. Along the way, he explains why staying calm, having a process, and staying invested can matter far more than finding the next winning forecast.
Key Points From This Episode:
(0:00:04) Introducing David Booth and his new book, Stay Calm: Learn to Embrace Uncertainty in Investing and Life.
(0:01:15) What David learned as a commission-based shoe salesman: Do the right thing and be upfront with people.
(0:03:35) The gift of being an outsider and how financial science changed the investing experience for ordinary investors.
(0:05:38) Why outsiders are often willing to challenge assumptions—and how data changed the debate.
(0:06:53) David's experience arriving at the University of Chicago and studying under Eugene Fama.
(0:07:49) Inside Chicago's rigorous research culture and the lessons David learned from presenting his work.
(0:10:03) The empirical challenge behind efficient markets and why data mattered more than beliefs.
(0:11:41) How Fama and French approach research by trying to prove their own conclusions wrong.
(0:12:05) The two-fish joke and the challenge of understanding the environment we are immersed in.
(0:12:45) How Jim Lorie and Lawrence Fisher helped provide the historical market data that transformed financial research.
(0:14:18) From early mutual fund research to the question that shaped David's career: What should investors do if managers cannot consistently outguess the market?
(0:20:59) Why Dimensional distinguishes between passive investing and indexing.
(0:23:21) The origins of Dimensional's approach to small-cap investing and the importance of execution.
(0:24:45) Why David would rather be an investor today than in 1971.
(0:26:21) Jensen's alpha, risk-adjusted returns, and what Michael Jensen's research revealed about professional money managers.
(0:28:30) Why implementation is everything—and why models are tools for making decisions under uncertainty. More from this podcast