Sorry, this post got long, bear with me.
I would agree with the both of these points made in this thread:
- Mustachians are less subject to inflation because of our inherent ability to maximize substitution bias. This is what we do, optimize spending.
- Mustachians are more subject to inflation because we already operate on a lower, more efficient budget which provides less options for substitutions
How can one agree with both? To the first point, when macro economic situations change we will be significantly more likely to adapt our spending habits and change with the times than the average consumer which the CPI is meant to track. Example, climate change causes double digit inflationary pressure on produce, we grow a garden because the ROI becomes greater. We will better and more quickly modify lifestyles to new inflationary pressures.
To the second, we will have less ability to fend off old, insidious, but continuous inflationary pressures. Example, the price of gasoline (although volatile) continuously increases slowly over time. Since this is historical and continual, mustachians have already significantly minimized driving and have little remaining ability to substitute.
I have not seen any significant discussion on other major advantages that mustachians have in a fight against inflation such as; capital, time, and self sufficiency. Time and self sufficiency provides mustachians with a greater than average ability to combat service related inflationary pressures. If plumbers suddenly double their rates, we would learn to DIY and have the time to do so. If rents in our prefered living area start inflating, we have the capital to purchase real estate and minimize future inflationary pressure on our housing costs.
All of this lends me to personally believe that Mustachians will likely experience inflation LESS than the CPI. Recency bias has us underestimating the effects of inflation over the long haul, it just been so low. I disagree with previous comments that this has little impact over a decade. It depends on the decade! If a mustachian only managed to reduce inflation's impact by 25 percent in the 70's then the 4% rule looks a lot better in those notoriously bad start years!
To clarify my position further. I realize that Joe & Jane consumer continue to have income, which is theoretically inflation adjusted. This is, of course, is the best inflation hedge of all. As a result, a retired mustachian without wage income will always be MORE at risk of inflationary pressures. My point is that when we are running our retirement scenarios on Cfiresim or the like and elect to take CPI adjusted increases we are
already factoring in this risk. If mustachian inflation is even slightly less than the average consumer with wage income protection, then over the period of a long retirement we are signifcantly overestimating our spending needs. We fight tooth and nail to reduce our ER on an index fund by 0.1%, but fail to take into account the huge impact taking only 75% of CPI withdrawal increases would have.