I saw a study a few years ago that compared the "wealthiest one percent" of that year to ten years prior. Very few of the names on the list from the past were still on the list.
There's a problem when you focus on income when trying to determine this stuff. Wealth doesn't work that well either. There was a news story the other day about how, strictly speaking, the "poorest man alive" with a net worth of like minus billions of dollars, had an income in the hundreds of millions. So what exactly are we talking about. Maybe: If you had to, today, exactly how many cheeseburgers could you get your hands on? Cuz for some people it is zero. For some it is many thousands. For others, it is all the cheeseburgers, they could literally buy them all, even yours.
Consider a man in middle management in an expensive area with a wife who doesn't work and 3 kids. He manages his money OK, but he bought in (as many of us have) to the idea that it is OK to borrow money to buy a house you can barely afford (in the expectation that future wage growth will relatively shrink that obligation) and it's OK to borrow money for a nice big "safe" family battlecruiser.
He makes 120k/yr after 15 years of working, his net worth is still negative, and everyone everywhere says he hasn't saved enough for retirement.
He thinks he's middle class, not because he has put any thought into it at all, but because he knows he isn't rich.
On Monday, he gets promoted to an executive position he had interviewed for but didn't expect to get. His salary goes from $10k/month before taxes to 80k/month after taxes PLUS options and bonuses. At that exact instant, is he booted out of the middle class? Or does he get booted out a year later?
Fast forward to 3 years later. As a humble man he didn't go nuts with that huge boon. He and his wife decide to pay off all debts and still keep their kids grounded. The car doesn't get upgraded, there's no helicopter to work. But the new position meant he wasn't home 75% of the year. His average workweek went from 50 hours a week to over 100 hours a week. He has a massive pile of cash in the bank, missed every soccer game and band concert. So he quits. The person he was 3 years ago said he needed x amount to retire, and he's there. In 10 years, his name won't show up on the list of the wealthiest 1%, cuz his income dropped to like nil. But he sure as shit isn't poor. Flying coach probably, buying toilet paper in bulk still. He earned 40 years of middle class wages in 18 years. He's actually just really really good at being middle class.
If this happened to you, think about it honestly, what would you do? I'd be gone. There is literally no amount of money you could offer me once I had "enough" to get me to stay. There are more people like this then you think. The proof is in the roster. People don't make seven figures for decades, on spec. You do it, then you get out, on to other things. I was not meant to be king, I'd rather have one more conversation with my grandfather than ever earn another dollar. Leave all that to the sociopaths.
Most of us normal folks aren't rich. Many of us can become pretty damn comfortable. One way of looking at it, I suppose, would be to look at your lifetime earning potential, given reasonable assumptions. If that lifetime amount has you living at cat-food levels, not middle class. If it has you living comfortable your entire life, but dying without leaving your heirs a fortune, you were middle class. If your children can quit their jobs once you die, you were upper middle class or upper class, but didn't pass on enough of the skills to make your children upper class. If your children never had to work, then you're wealthy.
The MMM crowd, I think, tend towards the sort that have a concept of "enough" and the discipline to not seek more as additional security. We'd rather invest time in our children instead of assuming they'll need our help financially. We are somewhat optimistic, and the outside looking in might call that naive. We are somewhat pessimistic, and the outside looking in might say we need to have more faith in ourselves.
I once wondered where all the wealthy people were. Is there a separate highway system? They aren't pulling meat out of the bargain bin with me at the grocery store are they? Where's their grocery store? In the US there are alot of super rich people, and alot of really really well off people. The ones that inherited it from the guy who invented the spork or whatever, they may not have "income" that gets them on the list. The reality is some of these people live next door to you, they go shopping or visit the whatever while you're at your job and out of their way. The secret to being wealthy, older I get, I am convinced, the secret is not spending your money. So the high earner big spender, they aren't necessarily wealthy, they aren't middle class either, they are definitely jackasses. I think there's people out there who could look at us decent earner/super savers as jackassess too, if we forego the high earning to...do...whatever.
As one of my friends said when I described what I've been working towards "Don't go all John Galt on us. We need you paying taxes."
I have things I want to do, but when I started down this road, I will freely admit, reducing the single largest expense I have in my life (taxes) is a huge motivator for me to manage to survive without any earned income. There's nothing righteous about that, there's an element of selfishness there, but I just don't care anymore. Your money or your life yo.
To the extent I ever think about it, I think of myself as being wealthy. I've earned a total of just under $400k total in my life, which puts me, if not in the top 1% of people alive today, certainly near the top 1% of humans who have ever lived. And it was easy, in retrospect. I fully acknowledge that there is a bit of luck. The cops didn't catch me doing that thing when I was young and stupid. The teacher gave me a second chance that one time when I was lazy. That stranger cared and helped when I needed it most. There were opportunities. But I am constantly amazed at just how amazing the world is right now, and how awesome my life is. I have a real possibility of doing whatever I feel like with no fear of dying of starvation, before my life is even half over. Regardless of what my net worth or income is at that point, I will be one of the richest people who ever lived. Stick that in your class war and smoke it.
Money=Time. Your money or your life.