Hopefully I don't get in trouble for "darn" since it's a direct quote...

Some progressives wanted to prove that the American dream is a myth. So they took a bunch of people in the bottom 10% of wage earners in Tennessee, then studied how many of their children ended up in the top 10% (the percentage was very low), and then said, "See, this proves there is little mobility."

Another statistic cited in The Millionaire next door is that 80% of Millionaires are first-generation millionaires, only 20% inherited their money.

How can both of these be true?

Here is why: Is it reasonable to expect someone from the bottom 10% to eventually grow their income and for their kids to make it to the top 10%? Not very likely. But does that mean that they didn't accomplish the American dream? No. Because if you are an immigrant or hard-working single mom who makes $11 an hour and puts your kids through school and gives them an amazing opportunity to get a college degree, then they make it to the top 50% and have an improved quality of life where they are making $70k a year and live in a middle class neighborhood, that is the American dream to me. They went from nothing to a situation that is better than half of Americans and 95% of the rest of the world. Then their kids can have a chance to make it in the top 10%. According to some, this would mean they have little class mobility.

People going from the poor house to millionaire status is mostly a myth. Even if they win the lottery or become a professional basketball player making $10M, more times than not this money gets squandered and is gone anyway. But it is very reasonable and true for individuals to improve their circumstances. My dad's dad was a coal miner. His son went to college (first one in his family), and became a software sales exec in the top 10%. But, he is still not in the 1%ers. I doubt I will be but others in my family may.

Also, it completely ignores the idea of "increasing the pie for everyone." Why do we care how much money billionaires have? We should care how the average person does. If Jeff Bezos has 8B or 80B it doesn't impact Joe Six Pack. Comparing success based on tiers and how much you make compared to others is inherently flawed. If my neighbor gets a bonus of 10K and I get a bonus of 5k per year, am I now poorer?

When it comes to the Book the Millionaire next door, most "self-made" millionaires or "Noveau Riche," were set up for success by previous generations. Even if they are the first ones in their family to be millionaires, it is very likely their parents worked up and had $500K to $800K for example, helped their kids pay for college, so they could become millionaires. This is also mobility to me.