&gt; You: The study was for the US, and never claimed to be otherwise, nor am I claiming otherwise.<p>&gt; Me: What you fail to grasp, and what I am pretty sure you are going to refuse to believe at this point, is the 4% rule applied as you and MMM are suggesting is the same trap of overfitting that many people who engage in backtesting do.<p><a href="http:&#x2F;&#x2F;www.financial-math.org&#x2F;blog&#x2F;2014&#x2F;04&#x2F;faqs-on-backtest-overfitting&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.financial-math.org&#x2F;blog&#x2F;2014&#x2F;04&#x2F;faqs-on-backtest-...</a><p>&gt; 5. I do not understand the meaning of backtest overfitting. If a strategy worked in the past, why shouldn’t it work in the future? Could you please provide a simple example?<p>&gt; Any random sample extracted from a population incorporates patterns. For example, after tossing a fair coin ten times we could obtain by chance a sequence such as {+,+,+,+,+,-,-,-,-,-}, where “+” means head and “-” means tail. A researcher could determine that the best strategy for betting on the outcomes of this coin is to expect “+” on the first five tosses, and for “-” on the last five tosses (a typical “seasonal” argument in the investment community). When we toss that coin ten more times, we may obtain a sequence such as {-,-,+,-,+,+,-,-,+,-}, where we win 5 times and lose 5 times. That researcher’s betting rule was overfit, because it was designed to profit from a random pattern observed in the past. The rule has absolutely no predictive power over the future, regardless of how well it appears to have worked in the past.<p><a href="http:&#x2F;&#x2F;blogs.barrons.com&#x2F;focusonfunds&#x2F;2014&#x2F;06&#x2F;13&#x2F;backtests-damned-backtests-and-statistics&#x2F;" rel="nofollow">http:&#x2F;&#x2F;blogs.barrons.com&#x2F;focusonfunds&#x2F;2014&#x2F;06&#x2F;13&#x2F;backtests-d...</a><p>&gt; The point: Investors don’t know how many hypotheses the managers examined, didn’t like, and chucked out, before they found the perfect backtest. The more the data is tortured, the likelier the result is just a fluke. So: How often is a fluke passed off as “alpha,” or some kind of amazing financial innovation?<p>-----<p>I&#x27;m just putting this here because you clearly missed the boat on my post and its possible others will to.