Someone else asked something like this recently (or stated that they would just adjust spending). I asked - and when and by how much and how long would you need to cut spending. They did not report back.
A lot of people just assume some adjustments will do it. It's not so easy. So here's some actual data. Hold onto your hats (you may need to sell those hats)...
I ran a 40 year profile in FIRECalc, using a $1,000,000 starting portfolio for easy math. "INVESTIGATE" tells me that an initial $46,182 (4.62%) spend will result in an ~ 70% success rate.
Then I cut the the years to 5, 4 then 3 to try to find where it dropped by 50%. I assumed that would be the 'alarm' to cut spending - but use whatever point you want. At year 4, one line dipped to $470K, close enough.
So then I added $23,000 of 'off-chart' inflation adjusted income in year 2022 (that might be one year off?). That would be the same as
cutting spending in half. How long did I need to do that to reach 100% for the 40 year period?
Any guesses? 5 years? No! 7, 10? No! 14 years!
So if you retired at 55 with a plan to cover the possibility of reaching age 95 (not uncommon for one of a married couple), that means
cutting spending in half from age 59 to age 73. And you can't get those years back.
Here's a link to play with: https://goo.gl/NQVNpB
For reference, a 100% successful WR for those 40 years was $33,413 (3.34%). Up to each person, but I'd prefer to start with $33,413 with a high confidence that I will not need to cut spending, versus $46,182, and possibly need to cut spending in half for a decade and a half.
edit/add: Another interesting point - while the 70% path starts out spending 38% more than the 100% path, but over the full 40 year period (after cuts to reach 100%), it amounts to an average of only 14.7% more. And the 70% path doesn't catch up in total amount spent until age 80.
-ERD50