> The people who work the hardest (e.g. single mother, people with 2 and 3 jobs) are not getting ahead as fast people who don't work as hard.
Sure. But I think this comes back to relative vs. absolute.
You aren't disagreeing that if an individual works more hours at any given job[1], all else equal, they will make more money.
I'm not disagreeing that there are individuals with different hourly pay rates.
Where we might disagree is whether there is a genuine positive correlation between skill level/scarcity of skill and hourly wage rate.
Also, I might have close to $0 in my bank account, but I don't really care that there are rich people out there and am not envious of them. It's enough for me that as I work harder, I will see the returns of my personal effort.
If instead one is really concerned about other people, then you've set yourself up for discontent, no matter how hard you work! I can practice basketball all day long and work hard, but I will never glide to the hoop as effortlessly as LeBron. And most people can practice programming all day long but will never be capable of doing the work at Facebook or Google.
It's important to know one's strengths and limitations. Go for the best hourly wage you can get, by all means, but that won't necessarily be $500/hour. And sure, there will be someone out there who can command that wage and make it look easy. You can focus on the cosmic injustice of this and make yourself unhappy, or you can do what you can to make your own life better.
> The economy isn't some lab experiment with double blind testing and so on. Any data you think you have is going to have some major fundamental flaws.
Well, if you believe this premise then it's not possible to submit evidence supporting any position, either mine or yours. I do believe there is some objective truth out there.
[1] Yes, salaried jobs don't have this characteristic directly, but only indirectly in the sense of getting a bonus or promotion. But those are also pretty good jobs relative to hourly jobs, which takes us back to square 1.