Looking at labor markets, my biggest concern is the drop in labor force participation. The data from the Labor Department on the employment-population ratio, for instance, suggest a permanent reduction in the share of the population that is working. And since economic output and living standards ultimately depend on thequality and quantity of labor and capital that is being productively utilized, it obviously is not good news that millions of people are no longer employed. But if I had to identify a second-biggest concern, it would be the “Europeanization” of long-run unemployment in the United States. Specifically, we have a...