The study was for the US, and never claimed to be otherwise, nor am I claiming otherwise.  If you start talking about other countries, you&#x27;re changing the parameters of the analysis.  Get the numbers for your target market and run the analysis.<p>And yes, <i>of course</i> you have to be prepared to adjust based on conditions.  You shouldn&#x27;t just blindly withdraw 4% every year.  Withdraw what you actually spend, and one of your many backup plans should be to <i>spend less</i>.<p>More to the point, fine, if you don&#x27;t think it&#x27;s safe, have other backups in place.  Work a few more years, or have access to means of part-time work, or build supplementary incomes, or any number of other solutions.  What&#x27;s your alternative proposal? &quot;This doesn&#x27;t work perfectly in all life circumstances, so give up and plan on retiring at 65&quot;?<p>Make plans to retire sooner than 65, and be prepared to adapt based on conditions.  If you make a plan to retire at 40, and something goes wrong, maybe you&#x27;ll retire at 45 instead.  Oh no, you&#x27;re only retiring 20 years sooner than everyone else; woe is you.<p>I&#x27;m not making optimistic assumptions; I&#x27;m making tentative assumptions and estimates that I can adapt over time.<p>For my particular case, for instance, it helps that while I&#x27;m saving like someone who wants to retire in my 30s, I don&#x27;t plan to quit when I get enough to retire.  I plan to keep working indefinitely, because I&#x27;m enjoying myself doing so.  But it&#x27;s sure nice to have backup plans, and to build a substantial excess for charitable purposes.