Re-running firecalc
This is the way I look at using firecalc. It isn't "god" and capabable of telling you 100% safe or not. There is a flaw in its modeling capabilities...
If you re-run and adjust upwards when the market is good, even if you always goto 100% safe, you are slowly putting yourself into the position to experience the worst case scenario. (You will run out of money)
If you re-run and adjust downwards when the market is bad until you get 100% safe, you are slowly putting yourself into the "best case" scenario (you'll die very rich).
If you re-run and adjust both ways, you'll be doing alot of hand waving and very little valuable work.
That isn't the way the tool should be used, the "valid run" case would be to run it in the middle of a up or down run. (When the market has recently returned *average* returns). Running it at the top or bottom, will lead to best/worst case computations. (Still *possibly* valid, but either very safe, or very risky).
Running firecalc after a major loss to see if you are *still* 100% isn't really a valid test, firecalc has no method of seeing the market has just lost 40%, and by the "law of averages" must come back to average at some point.
Running firecalc after a major upturn to see if you are *now* 100% isn't really a valid test either. Once again firecalc can not tell that the market has just gained 50% in the last 3 years.
Thats the danger of using past data, to predict future, based on the present.
Unless firecalc looks at current (present) market to determine if we are above average, or below average (based on what? some number of years?) it can dangerously say you are 100%, when you may not be. Or less than 100% when you in fact still safe.
Laters,
-d.