The Father of the 4% Rule Says Retirees Can Take Out Much More

在《The Motley Fool》播客节目“Hidden Gems Investing Podcast”中，威廉·本根（William Bengen）——常被誉为“4%法则之父”——接受了罗伯特·布罗坎普（Robert Brokamp）的采访。他在采访中讨论了自己的最新研究，该研究表明大多数退休人员在退休第一年可以安全地提取的金额，远超普遍接受的4%。 本根最初是一名航空工程师，在40多岁卖掉家族企业后转行从事财务规划。他在20世纪90年代初开始了他的开创性研究，因为他发现客户，特别是即将退休并询问他们可以安全花费多少钱的婴儿潮一代，严重缺乏指导。随着人们寿命的延长，制定稳健的提款率策略变得至关重要。 他1994年的初步研究利用历史市场数据和Lotus 1-2-3电子表格，确定了一个“安全最高”提款率为4.15%，后来在2006年修订为4.5%。“4%法则”虽然获得了广泛认可，但本根指出，它常常是对他不断发展的工作的误读，未能捕捉到大多数退休人员可以提取更多金额这一细微之处。 本根的最新著作《更富裕的退休生活：增强4%法则以花更多钱享受更多》（A Richer Retirement, Supercharging the 4% Rule to Spend More and Enjoy More）反映了他将安全最高提款率更新至4.7%。这一增长主要归因于他的研究纳入了更复杂、更多样化的投资组合，将资产类别从两种扩展到七种。他认为，即使是4.7%也可能被低估了，如果进一步分散投资于另类投资，这一比率可能会达到5%或更高。 至关重要的是，本根强调4.7%是一个*最坏情况下的假设*，代表了能够经受住（自1926年以来）最不利历史条件的提款率。从历史上看，*平均*安全提款率超过7%，在某些最好的情况下（例如1932年7月退休，当时市场极其便宜），提款率甚至高达15-16%。他指出，历史上5.5%的提款率有90%的时间是成功的，而6%的提款率有75%的时间是成功的。 影响安全提款率的两个关键因素是： 1. **市场估值（CAPE比率）：** 在迈克尔·基特西斯（Michael Kitsis）研究的基础上，本根发现股票市场估值（使用席勒市盈率，即CAPE比率）与安全提款率之间存在很强的相关性。市场便宜时允许更高的提款率（例如，2009年退休者可达8%），而市场昂贵时则需要更保守的方法。目前，由于CAPE比率较高，提款率将倾向于降低。 2. **通货膨胀：** 高通胀会大幅降低安全提款率。历史上最糟糕的情况（4.7%）发生在1968年退休的人身上，他们先是经历了连续的熊市，然后又面临了十多年的高通胀。相比之下，1929-1932年更严重的股市崩盘对提款率的损害较小，因为它是一个通货紧缩时期，允许退休人员减少提款。本根建议，在当前中等通胀、加上高CAPE比率的环境下，5.5%左右的提款率可能比较合适。 采访还强调了关键的“收益序列风险”，指出退休后的前10-12年至关重要。早期的熊市可能严重扰乱退休计划，而退休后期发生的市场低迷影响则不那么严重。 本根讨论了几个个性化提款规划的要素： * **灵活提款方案：** 调整提款（在困难时期减少支出，在景气时期增加支出）是一种自然且有益的策略。 * **时间范围：** 提款率对规划期限高度敏感。虽然30年退休期（65-95岁）通常符合4.7%的法则，但10年期限可以支持8%的提款率。对于非常长的退休期（例如60年），提款率不会远低于4.1%。 * **资产配置：** 多样化的投资组合（本根的基本案例使用55%的股票分散在五个类别，40%的中期债券，5%的国库券）至关重要。虽然较高的提款率需要最低限度的股票配置，但过高的配置（尤其是非多样化的）在深度熊市中可能会适得其反。目前的研究表明，65%的股票配置可能更有益。持有过多现金（回报率较低）会降低安全提款率。 * **再平衡：** 每年对投资组合进行再平衡在各种市场条件下似乎都是最佳选择。 * **滑翔路径：** 本根还讨论了有研究表明，在退休期间每年*增加*1-2%的股票配置（从较低比例开始）可能是有利的，因为这可以减少早期熊市的风险敞口，并允许在后期进入上涨市场时进行积极买入。 最后，本根结合自己十多年的退休经验，建议人们在生活中培养四个关键方面：家庭、朋友、健康和爱好。忽视其中任何一个都可能降低生活质量。他对研究的慷慨分享和深思熟虑的回应使他成为退休规划领域备受尊敬的人物。

In an interview with Robert Brokamp for The Motley Fool's "Hidden Gems Investing Podcast," William Bengen, often hailed as the "father" of the 4% rule, discusses his latest research, which indicates that most retirees can safely withdraw significantly more than the widely accepted 4% in their first year of retirement. Bengen, originally an aeronautical engineer, transitioned into financial planning in his 40s after selling his family business. He embarked on his seminal research in the early 1990s because he found a severe lack of guidance for clients, particularly Baby Boomers, who were approaching retirement and asking how much they could safely spend. With people living longer, the need for robust withdrawal rate strategies became critical. His initial 1994 research, using historical market data and Lotus 1-2-3 spreadsheets, identified a "safe max" withdrawal rate of 4.15%, later revised to 4.5% in 2006. While the "4% rule" gained widespread recognition, Bengen notes it's often a misrepresentation of his evolving work, failing to capture the nuance that most retirees could withdraw more. Bengen's latest book, "A Richer Retirement, Supercharging the 4% Rule to Spend More and Enjoy More," reflects his updated safe max of 4.7%. This increase is primarily due to his research incorporating more sophisticated, diversified portfolios, expanding from two asset classes to seven. He believes even this 4.7% could be an understatement, potentially reaching 5% or higher with further diversification into alternative investments. Crucially, Bengen emphasizes that 4.7% is a *worst-case scenario*, representing the rate that would have survived the most adverse historical conditions (since 1926). Historically, the *average* safe withdrawal rate has been over 7%, with some best-case scenarios (like retiring in July 1932 when markets were extremely cheap) allowing for withdrawal rates as high as 15-16%. He points out that withdrawing 5.5% has been historically successful 90% of the time, and 6% has worked 75% of the time. Two key factors significantly influence the safe withdrawal rate: 1. **Market Valuation (CAPE Ratio):** Building on research by Michael Kitsis, Bengen found a strong correlation between stock market valuations (using the Shiller CAPE ratio) and safe withdrawal rates. Cheap markets allow higher withdrawal rates (e.g., 8% for a 2009 retiree), while expensive markets necessitate more conservative approaches. Currently, with a high CAPE ratio, rates would lean lower. 2. **Inflation:** High inflation dramatically reduces safe withdrawal rates. The worst historical case (4.7%) occurred for a 1968 retiree who faced consecutive bear markets followed by over a decade of high inflation. In contrast, the much deeper stock market crash of 1929-1932 was less detrimental to withdrawal rates because it was a deflationary period, allowing retirees to reduce their withdrawals. Bengen suggests that in today's medium-inflation environment, coupled with high CAPE, a withdrawal rate around 5.5% might be appropriate. The interview also highlights the critical "sequence of returns risk," emphasizing that the first 10-12 years of retirement are paramount. An early bear market can significantly derail a retirement plan, whereas market downturns later in retirement tend to have less severe impacts. Bengen discusses several elements for personalized withdrawal planning: * **Flexible Withdrawal Scheme:** Adjusting withdrawals (reducing spending in tough times, increasing in good) is a natural and beneficial strategy. * **Time Frame:** The withdrawal rate is highly sensitive to the planning horizon. While a 30-year retirement (65-95) often aligns with the 4.7% rule, a 10-year horizon could support an 8% rate. For very long retirements (e.g., 60 years), the rate doesn't drop much below 4.1%. * **Asset Allocation:** A diversified portfolio (Bengen's base case uses 55% stocks across five categories, 40% intermediate bonds, 5% T-bills) is crucial. While a minimum stock allocation is needed for higher rates, too high an allocation (especially undiversified) can be counterproductive during deep bear markets. Current research suggests a 65% stock allocation might be even more beneficial. Holding excessive cash, which offers lower returns, reduces the safe withdrawal rate. * **Rebalancing:** Rebalancing portfolios annually appears to be optimal across various market conditions. * **Glide Path:** Bengen also discusses research suggesting that *increasing* stock allocation by 1-2% annually through retirement (starting lower) can be advantageous, as it reduces early bear market exposure and allows for aggressive buying into rising markets later. Finally, drawing from his own decade-plus in retirement, Bengen advises cultivating four crucial aspects throughout life: family, friends, health, and passions. Neglecting any of these can diminish life quality. His generosity with research and thoughtful responses have made him a respected figure in retirement planning.