China’s auto industry is becoming a monument to the pitfalls of industrial policy. In “Sizing the Foreign Manufacturing Spillovers from China’s Overcapacity,” Goldman Sachs reckons Chinese car exports now account for a tenth of the world market. That convergence is precisely what gives industrial policy its “horseshoe” quality. Industrial policy, in short, has become the point where populists of left and right meet, curving toward each other. Industrial policy may help jump-start infant industries in some cases, especially in emerging markets, but Beijing’s oversupply shows the danger of dictating their adulthood.