There's a lot of discussion about income mobility today, but most of it blurs the real facts. For example, Kevin Drum writes that
life roles have become more hardened. While incomes of the well-off have skyrocketed over the past 30 years, working and middle class incomes have stagnated. At the same time, the incomes — and jobs — they do have are far more unstable than they were a few decades ago. And as recent research indicates, most of them are increasingly stuck in these grim circumstances: every decade, fewer and fewer of them — and fewer and fewer of their children — have any realistic chance of moving up the income ladder.
There are several problems here. First, Drum doesn't mention the word 'immigrants.' The U.S. has accepted an enormous number of immigrants over the past thirty years, most of them coming from poorer countries. Is he really saying that the children of the immigrants are not better off than their parents?
Second, Drum blurs together the past thirty years. The reality is over the past ten years, the poor and lower middle-class have shown the biggest income gains since the early 1970s. Incomes of the lower middle class are up 12-13% over past ten years, compared to flat or so over the previous twenty.