In a May 2010 analysis of withdrawal rates by Craig L. Israelsen in financial-planning.com magazine, the author found that over 16 25-year periods from 1970-1994, 1971-1995 etc...through 1985-2009 a 5% withdrawal rate, increased annually by 3% for inflation, and starting with $100,000 did not run out of money.
Of-course, there were many years in the first 13 of the 16 periods used that experienced inflation that was higher than 3%. This always begs the question of what your spending will really be like in retirement. It is a factor that we all can exercise some control.
Another aspect, is the bond/stock mix. As Israelsen states "...diversification should be a key attribute of every portfolio at every point in the life cycle...". A 100% bond portfolio did not keep up with inflation but never went to zero. A 60% bond and 40% stock portfolio performed better and the reverse, a 60% stock and 40% bond portfolio up to a 75% stock and 25% bond portfolio had even higher ending account balances and never went to zero during the 25-year period.
We cannot control inflation and the market conditions but we can control our asset allocation mix and our expenses. Manage what you can control. The "...multi-asset portfolio survived in all 16 rolling 25-year periods..." at a 5% withdrawal rate and even at a higher 8% withdrawal rate.
These withdrawal rates (of 5% and 8%) are quite in this academic exercise but sometimes erring on the side of such a conservative withdrawal rate of 4% - which is just a rule-of-thumb anyway - could mean drastic changes to lifestyle in retirement.
The $100,000 portfolio during the 1975-1999 period increased over 25 years to more than $1.5 million (remember, though, that the inflation rate was fixed at 3% and was not the rate experienced during that 25-year period). However, during the 1984-2008 period the $100,000 balance ended at $400,000.
It is true that when you begin to take withdrawals matters based on market conditions.