Pitfalls in Retirement (pdf) is quite a good white paper from Meril Lynch, I strongly recommend it.
could safely spend 10% or more of their savings each year.
But, as explained below, the respondents most on target were the one in 10 who estimated sustainable spending rates to be 5% or less. This is significantly impacted by life expectancy; if you have a much lower life expectancy due to retiring later or significant health issues perhaps you can spend more. But counting on this is very risky.
This is likely one of the top 5 most important things to know about saving for retirement (and just 10% of the population got the answer right). You need to know that you can safely spend 5%, or likely less, of your investment assets safely in retirement (without dramatically eating into your principle.

The chart is actually quite good, the paper also includes another good example (which is helpful in showing how much things can be affected by somewhat small changes*). One piece of good news is they assume much larger expense rates than you need to experience if you choose well. They assume 1.3% in fees. You can reduce that by 100 basis points using Vanguard. They also have the portfolio split 50% in stocks (S&P 500) and 50% in bonds.
Several interesting points can be drawn from this data. One the real investment returns matter a great deal. A 4% withdrawal rate worked until the global credit crisis killed investment returns at which time the sustainability of that rate disappeared. A 5% withdrawal rate lasted nearly 30 years (but you can’t count on that at all, it depends on what happens with you investment returns).
Related: What Investing Return Projections to Use In Planning for Retirement – How Much Will I Need to Save for Retirement? – Saving for Retirement