The headline on the front page of the Thanksgiving Day The New York Times: “Opening Day for Holiday Shopping Shows Divide.”

The next day – Black Friday – Bloomberg ran a story with the headline “U.S. Workers’ Pay Slide Poses Consumer Risk. ”

It may turn out to have been a “Black Friday” for top end retailers, but it’s a bleak season for low income America and the businesses that cater to it. According to the Times’ story: “Wal-Mart’s profits declined in the third quarter as it kept many prices low so its shoppers could afford them.” Michael T. Duke, Wal-Mart’s chief executive, told analysts that ‘There is a real sense that the economic strain is taking its toll.” Without the fuel of credit that had increasingly been required to power spending by low-income workers, Wal-Mart now has to resort to layaway plans for its shoppers.

As 10 percentage points of national income has been directed away from the bottom 80% to the top 1% since 1979, those paid the lowest wages have seen their buying power erode the most. While the quality and quantity of education force can explain much of the distribution of income within the bottom 99% (together with personal networks, effort and luck), differences in educational attainment have nothing to do with the transition of the American economy to extreme inequality since the 1970s. It is also quite clear that among developed countries, America is exceptional: only the UK comes close to US-style extreme inequality.

The lesson is that extreme inequality is the outcome of political choices that have empowered a tiny minority. It has to do with political choices, the way institutions function, and social norms; it is not a natural market payoff to investments in education. The shift of income to the top .1% (which has driven the growth of the top 1%) reflects the market power of a small number of CEOs and finance, medical and legal professionals.

Here are some metrics that focus on what has happened to the wage/salary earnings of American workers.

Employee compensation in the . . .

Read more: The Metrics of Protest: Black Friday and Low-Wage America