Mr. Gross insists the doomsayers are wrong. Since the economic meltdown of 2008-2009, he says, the American economy has made a dramatic turnaround. Corporate profits, exports and the stock market have skyrocketed to record levels. The private sector has created more than 4 million new jobs. Tourism has boomed. The U.S. auto industry has come back with a vengeance, and GM is selling even more cars in China than it does at home. American farmers are shipping rice to Japan, soybeans to China and beef to Brazil. Apple, Google and Facebook are setting the standard and the pace of innovation for the world.