Twenty years ago, when I started out as a writer, the problems of mass prosperity were the ones that intrigued me most. America was then, as I thought it would always remain, the great middle-class nation. And in the permanent affluent society, questions of taste and waste and marketing and alienation were what really mattered, now and forever. When moved to consider workplace issues in those days, I instinctively placed them in the category of brutal-things-settled-long-ago: Without even thinking about it, I connected the word "labor" to the word "history."

It's not a mistake anyone can make any longer, whether they are pondering the voting patterns of working-class Hoosiers or the driest statistics in the record book. Median "nonelderly" household income, we find, fell consistently through the first half of this decade, despite the solid economic growth enjoyed by the country as a whole.

Some nonmedian folks did just fine, of course: The top 20% of households earned more, after taxes, than the rest of the country combined in 2005, while the topmost 1% of the population took home more than the bottom 40%. The top-earning hedge fund manager of 2007, in fact, made about as much last year in nominal dollars ($3.7 billion) as J. Paul Getty, one of the richest men in the world, was worth in the mid-1970s.

Real hourly wages for most workers, on the other hand, have risen only 1% since 1979, even as those workers' productivity has increased by 60%. What's more, American workers now clock more hours per year than their counterparts in virtually every other advanced economy, even Japan. And unless you haven't read a newspaper for 15 years, you already know what's happened to workers' health insurance and pension plans.

I confess that I am fascinated by the mechanics of this huge social reconfiguration – in the same sense that I am fascinated by the industrial procedures of a slaughterhouse, or by the strategies that enabled small Confederate armies to win victories for slavery over much larger Union forces. How the big change was brought off is the subject of Steven Greenhouse's important new book, "The Big Squeeze," which is also my source for many of the statistics in the preceding paragraphs. Aside from the outsourcing, offshoring, and firing-at-will that make up the best-known weapons in the corporate arsenal, Mr. Greenhouse reveals how managers extract unpaid work through an array of ingenious tricks, from eliminating bathroom breaks to electronically erasing hours from workers' records.