So if you want to claim that output per hour is the true appropriate measure of a country’s income, then you have to reckon with the uncomfortable fact that America’s output per hour has soared while West Europe’s has grown only slowly. It’s this slower growth in productivity that’s precisely why some European leaders and intellectuals are sounding the alarm over the region’s growth rate and policy regime. So no matter which way you slice it, the economic comparison between Europe and the U.S. doesn’t come out looking great for Europe. Yes, in terms of nonmonetary factors — crime, road safety, drug use — Europe is a nicer place. But Americans are richer in material terms, and their productivity is growing much faster. That’s definitely a gap Europeans should be worried about. Being a “garden” — a leisurely, comfortable, senescent civilization — was a luxury Europe could afford in the peaceful decades of yore. But not anymore.