pioneering work on assessing inequality in the U.S., has just released his latest study, bringing his data up to 2012. His finding: The income share of the top 1 percent of earners in 2012 returned to the same level as before both the Great Recession and ...the Great Depression: over 22 percent. The study also shows that almost all the gains over the last 20 years have gone to the very top. Between 1993 and 2012, the real incomes of the top 1% grew 86.1%, while those of the bottom 99% grew 6.6% (the top 1% is defined as families with incomes above $394,000 in 2012). From 2009 to 2012, as the U.S. economy improved, incomes of the top 1% grew more than 31%, while the incomes of the 99% grew 0.4% - less than half a percentage point. Meanwhile, the typical worker saw almost no income gain at all. And we now have the lowest percentage of adults in the workforce than at any time in the last 35 years. As I've argued, all this is not only savagely unfair but it's also bad for the economy. With so much of the nation's economic gains going to the top, the rest don't have the purchasing power to keep the economy going -- which explains why the recovery has been so anemic, and why it's also so fragile. This degree of inequality is also bad for our democracy: With so much income and wealth concentrated at the top, the rich have been able to entrench their wealth and privilege through laws that favor them and their businesses while putting ever-greater burdens on everyone else. The question is: When do we reach a tipping point? When is inequality so wide that the vast majority of Americans refuse to take it any more? Is the upcoming mayoral race in New York -- centered as it has been on inequality, with the putative winner pledged to raise taxes on the City's wealthiest -- a sign of things to come? .