This is a good faith question: I often hear advocates of unions claiming that unions are “good for the economy.” What is the proof of this? Is there much well-regarded research that shows that unions improve productivity or enhance competitiveness? If so, which unions? which sectors? I can imagine that the better working conditions achieved in part by labor organization in the 1920s and 1930s were ultimately beneficial to the economy. But what about today? Because when I hear Democrats talk about helping unions as way to improve our economy, all I ever hear are platitudes.

Now, it’s important to note that the case for unions does not rise and fall on this question. You can make the case that unions are good according to other priorities that fall under the jurisdiction of “social justice” and all that. I certainly think China would be better off if it had strong(er) and independent labor unions. But as a purely economic matter, where’s the evidence that unions actually improve the efficiency, productivity, or competitiveness of specific firms or industries or the nation as a whole?