Economist: SOME HISTORIANS BELIEVE that Marco Polo never went to China. But even if the 13th-century Venetian merchant did not lay eyes on the coastal city of Hangzhou himself, he certainly reflected the awe it inspired in other foreign traders when he described it as beyond dispute the finest and the noblest in the world. And, incredible as it may seem, he wrote, Hangzhou (which he called Kinsay) was but one of more than 1,200 great and wealthy cities in southern China. Everything appertaining to this...