Originally Posted by LARS
At the end of the day this is an issue that is more art than science and so must be actively managed with mid-course corrections as many have stated. I suppose to be on the safeside of this issue, an other aspect is that "excess" spending should be tilted toward "tangible" assets (i.e. homes/art) as they can always be liquidated to cover future expenses if you've "over-spent".
This is another area where, if you *want* to increase spending if you thought you could do so safely, a form of the "one more year" syndrome can rear its ugly head. You may think you're fine now, but you'll hold off "one more year" to start increasing your burn rate. (Never mind that you could be dead in "one more year.")
Obviously, if someone has more than enough and really doesn't have the desire to spend more, it's a moot point but for those who do, this is very similar to the decision as to when to retire because it requires you to determine that you "have enough" (plus some delta for safety, perhaps) before taking the plunge.