I had not heard of this model by name before today.
However, I already believed that it was true.
When I started my career in 1982, my dad (an accounant) encouraged me to develop a tracking sheet for what I spent money on. I didn't keep it up - took WAY too much time. But I did it semi-regularly for a few years. And just recently I found, in old boxes, those documents. Reading them was an eye-opener.
In almost all categories, I spend less today than in 1982. I'm not adjusting for inflation when I say that! Actual dollars out of pocket. How could this be true?
Some it is technology. Some of it is simply how the human body reacts.
Here are some examples:
Gasoline: In 1982, $1800 per year. Breakdown: I drove 25,000 miles a year, gasoline was about $1.50 and the car (a 10 year old Chevy with 70k miles that my folks gave me) got 13-14 MPG.
Today: $1600 per year. Breakdown: Myself and my wife together drive 15,000 miles per year, I figured gas at $3, and I used the lowest MPG of our three vehicles, my hot rod at 27MPG. If I actually averaged the MPG of my car and the wife's, we get the actual spend from Quicken, which is $1100.
Why the reduction in miles driven? In 1982, I was fresh out of college and in a new town and the only way I could think of socializing (to meet women) was clubbing and other activities involving spending money. When I did go on a date, I was most likely to take her somewhere for a weekend - the coast or at least a few cities over to see a gorgeous park/valley/mountain that would be outside our immediate citiy's daily experience. Nowadays, while I do enjoy driving ye olde hot rod, if I don't happen to be carving up the switchbacks going uphill fast, I now view most driving as a means to get stuff done, and seek ways to minimize it.
Car insurance: 1982, $5000/year for one car. Today, $1200/year for 3 cars. Why? In 1982 I was a single male, early 20s, clean driving record. All single males paid horrible prices then. All I had was an old Chevy. Today, I'm married, old, have an at-fault accident on my record, but also don't live in the city. My deductibles are no different, the value of the cars is much higher.
Automobile purchase/depreciation. Somehow I figured out early on that buying cars new and replacing often probably would hamper my ability to spend on other stuff. So, from 1982 until 2014, I spent between $3500 and $7000 on cars, never outside that range. Had I found a car exhilarating enough, I'd have spent more, but not a lot.
But, a $5,000 car in 1982 would be a 3-5 year old car that I'd get 3-5 years out of before it started requiring substantial maintenance and repairs. Today, I can find $5,000 cars that have another 100,000 miles of low-cost ownership in them. Cars are that much better. I keep a log of every car I've owned and with a few exceptions, every newer vehicle has cost less per year/mile than the previous ones. What are the exceptions? Cars with lots of accessories, upmarket models, European models. Mostly I drive 4-cyl manual transmission cars. In 2014, I decided I wanted us to splurge, so we bought our first new car, my wife's Prius in mid-2015, and later I bought my mid-life crisis car, which was an '013 so it was used, just not as used as I usually get.
Food: $600/mo 1982, $700/mo today for two adults. What? But hasn't food gone up a lot? Sure, but I'm older. Because of a nearly life-long battle to lose the last 30 pounds, I track calories every few years, determining at what daily intake my weight is stable. In 1982 it was 3300 calories per day, today it's 1600. And in 1982 I was sedentary, whereas today I run a few miles 3-5 times a week and am outdoors a lot more. My wife is petite and simply doesn't need much to maintain.
The metabolism slows as we age - a lot. For some folks who don't adjust, this leads to obesity, but if you watch your weight, it leads to spending reductions.
Electricity and gas: In my 20s, I left lights on, now I don't. I've also realized light-colored walls prevent the need for artificial light in the daytime. I've also gotten better at managing airflow. Plus, new buildings are more efficient, and if you own an older one (as I do), we know more about insulation/sealing, etc. My utility bills in 1982 were $350 for a 1200 square foot half of a duplex. Today, 1800 square feet, avg heating/cooling is $120/mo. Electricity prices went up, but I use less of it.
Category after category works out like that. I'm wiser in some cases, and in other cases, technology makes the win.
The biggest exception: The Phone. $12/mo in 1982. Today, $85/mo for two cell phones. Plus - we now pay $50/mo in internet access, something that didn't exist in '82. I've never had cable TV at all, so it costs the same today as in '82.
Health care: in '82, insurance plus regular visit was about 10% of my gross income. Today, for the two of us, it's about 10% of the gross income I earned until I quit working. Then the insurance cost went down, visit costs went up, but total is the same. We are on ACA with a high-deductible plan. But, I also have to note that the stuff we've paid for recently didn't even exist in '82...new tech in this case gives us more stuff to spend on.
I've chatted with similar -aged friends who have observed their own spending, and I've found no exceptions.