For decades, American workers have watched as their ability to enjoy middle class lifestyles erodes away. Conventional explanations abound. American industry in the immediate aftermath of World War II was uniquely unscathed, and with a near monopoly on global manufacturing, it was able to pass much of the ample profits on to workers. It wasn’t until the 1970s that American manufacturers confronted serious foreign competition, and ever since, the competition has only become more intense…