Not sure I agree. Trinity study suggests that if you retire 30 years before death, you can safely withdraw 4% every year during retirement, regardless of economic fluctuations. If you retire super early and need 50 or 60 years, your safe withdrawal rate is probably closer to 3% or even 2%, though.

Your point may be that we should expect significant economic turmoil in the near- and medium-term, much more than "fluctuations", which may be true, or may not be. Impossible to predict the future.

Consider that the 2021 inflation rate is likely a symptom of COVID. Monthly inflation rates for the last few months of 2021 were trending downward. Hopefully we can expect inflation to get back to something approaching normal by the end of 2022. Even if it takes a couple more years, there's no reason to expect that 7% inflation is the norm going forward.

(Also consider that people who are doing FIRE certainly don't have much in treasuries. It's going to be mostly in stocks. That certainly carries other risks, of course.)

> Consider that the 2021 inflation rate is likely a symptom of COVID

It's mostly a symptom of reckless monetary and fiscal policies.

> Monthly inflation rates for the last few months of 2021 were trending downward

It's the opposite if CPI is to be believed (which is a big if): https://www.bls.gov/charts/consumer-price-index/consumer-pri...

> It's mostly a symptom of reckless monetary and fiscal policies.

... as a result of the pandemic...

The US public will not tolerate sustained high inflation. Congresspeople and presidents who push monetary and fiscal policies that increase inflation (and nominate Fed leadership that do the same) will get voted out over time.

Your chart measures a 12 month trailing computation. That number going up does not imply that the month-by-month inflation is actually going up. If that number went up in December all it means is that December 2021 had more inflation than December 2020. It says nothing at all about the relative inflation between November 2021 and December 2021.

Wow I never heard of the "Trinity Study", its a report written 25 years ago by a few guys at a small university I've never heard of. Remember back then bond yields were 5% and inflation was 2%, Clinton was president and the dotcom boom was really starting. Things are very different now.

https://en.wikipedia.org/wiki/Trinity_study

I don't think "things are very different now" is a refutation of the study without providing more specifics. It's also been repeated more recently, with updated data. The 30-year results, I believe, still hold, but as I note, if your retirement horizon is much longer than 30 years, you'll have to be more conservative with your withdrawal rate.

S&P 500 returned ~25% this last year, and 110% over 5 years. That's excluding dividends.

That is actually, quite literally, inflation. It's money depreciating in value relative to stocks and financial products. Just like a burger at the golden arches shooting up in price is inflation, so is the price of a stock. It's probably not _only_ inflation, supply and demand will have caused the majority of this shift, since savers saw their money start evaporating. But that is of itself of course a second order effect of inflation, so I think the point stands.

Sure, but the only kind of inflation that really crushes people living off their investments is stagflation, where increasing prices of goods is not reflected in portfolio sizes. If your investments are growing way faster than the price of goods, there is no problem.

To be fair we are living in a crazy unprecedented strong bull market. It will be interesting to see how this holds.