Ah, but now that your argument is based on decreasing returns we can just do expected value analysis.<p>Fortunately, many people have already done this, including Betterment: <a href="https:&#x2F;&#x2F;www.betterment.com&#x2F;resources&#x2F;personal-finance&#x2F;safety-net-funds-why-traditional-advice-is-wrong&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.betterment.com&#x2F;resources&#x2F;personal-finance&#x2F;safety...</a><p>Weighted by the probability of happening, you are better off investing all your money. Period.