Okay. Lets take a 1 million dollar retirement portfolio that is in a mixture of bonds/equities/property.
The retiree retires at 30 years old and lives to 90, withdrawing 4% / $40000 per year
In what scenario would they run out of money?
well... too many unknowns to give you a clear answer, but if you take fireCalc's defaults, over a 60 year period the portfolio will run out of money in 18% of the historical periods. That's assuming 75% equities, 25% bonds.
The results will change if you change what % you have in bonds/equities, and if you include property and include money from SS when the retiree hits 62 or 65 or 70 (all 30+ years into retirement).
It's worth noting that at the 30 year mark, about 2/3 of the simulations have a much higher balance than the original $1M.
Also, as smart, thinking adults, we have the power to change things if we retire and then suddenly there is the worst economic conditions in a century. We can cut our spending, or find temporary part time work - all of which will greatly add to our chances of success.