The information sector may have glamour and manufacturing, nostalgia appeal, but the real action in high-wage job growth in the United States is in the vast realm of professional and business services. This is not only the largest high-wage part of the economy, employing just under 20 million people at an average salary of $30 an hour, it’s also one the few high-wage sectors in which employment has expanded steadily since 2010, at more than 3% a year, adding nearly 3 million white-collar jobs.