Our guest on the podcast today is William Bengen. Bill has been a prolific researcher of retirement planning matters over his career, and he pioneered the exploration of safe withdrawal rates with his groundbreaking 1994 research that gave birth to what's now called the 4% rule. Bill is the former owner of Bengen Financial Services, an independent Registered Investment Advisor that he launched in 1989, after his family sold the soda-bottling business that he had helped manage. He received his Bachelor of Science degree in aeronautics and astronautics from MIT. Bill retired from his financial planning practice in 2013 but continues to conduct research on retirement planning and withdrawal rates. We're excited to have him here today.BackgroundBioIn-Retirement Withdrawal Rates and Asset Allocation“The Originator of ‘the 4% Rule’ Thinks It’s Off the Mark. He Says It Now Could Be Up to 4.5%,” by Neal Templin, barrons.com, Jan. 23, 2021.“The Planner’s Toolkit for Managing Retirement Withdrawal Plans,” by William Bengen, financialplanningassociation.org, April 2021.“Resolving the Paradox--Is the Safe Withdrawal Rate Sometimes Too Safe?” by Michael Kitces, kitces.com, May 2008.“Bill Bengen Revisits the 4% Rule Using Schiller’s CAPE Ratio, Michael Kitces’s Research,” by Bill Bengen, fa-mag.com, Dec. 17, 2020.“Can We Raise Our Safe Withdrawal Rate When Inflation Is Low?” earlyretirementnow.com, Oct. 26, 2020.“Economic Outlook: Still Rising,” by Preston Caldwell, Morningstar.com, Oct. 3, 2021.“Jonathon Guyton: What the Crisis Means for Retirement Planning,” The Long View Podcast, Morningstar.com, June 17, 2020.“Determining Withdrawal Rates Using Historical Data,” by William Bengen, retailinvestor.org.“The Rules of Retirement Spending Are Changing,” by Anne Tergesen, wsj.com, Nov. 26, 2021.“Choosing the Highest Safe Withdrawal Rate at Retirement,” by William Bengen, fa-mag.com, Oct. 1, 2020.