[froindt]

I agree, but to add a few more details:

* This is typically cited from the Trinity study (https://en.m.wikipedia.org/wiki/Trinity study).

* It is looking at a 30 year time horizon. For longer periods you'd need a but more money, but not double. 3% is incredibly safe, and wouldn't take that much longer to acquire once you're at 4%.

* Slight reductions in expenses during down years have a huge effect on the overall success of the portfolio. If you could reduce expenses to 3.5% during severely down years, that would significantly help the success and longevity of your portfolio.