Travel and tourism is a cornerstone of the global economy. It already accounts for 10.2 percent of global GDP, and 292 million jobs. And the sector is growing rapidly, thanks to the expanding global middle class, improved digital and physical connectivity, and human curiosity. If travelers spread out around the world evenly, tourism would be relatively easy to absorb. Of course, that is not the case, now or likely in the future. By 2020, the 20 most popular countries will add more international arrivals than the rest of the world combined (exhibit).