Slate columnist Matt Yglesias posted the above chart yesterday  as part of a post arguing that  ”America’s Private Sector Labor Unions Have Always Been in Decline“. He notes:

[P]rivate sector labor unions have been in decline in the United States pretty consistently since World War II. There was a little uptick associated with the Great Depression, but really mass private sector labor unionism in the United States was an element of wartime economic planning. Then, in the immediate postwar years, we were at something of a political economy tipping point. We could have become a country where the overwhelming majority of large private sector firms were unionized, but instead congress passed the Taft-Hartley Act. It’s been a long steady decline since then, partially masked by the unionization of a large swathe of public sector workers in the 1960s.


But back to the chart. The important point it makes, I think, is that it’s essentially always been like this. There’s been no sustained period of time when the political or economic landscape was favorable to a growing union share in the workforce. There was a large, one-off increase in union membership associated with the coincidence of a major gloabl (sic) war and a Democratic Party administration. My understanding is that there was a similar unionization surge during World War I. So anyone looking for a peacetime surge in union membership (I don’t see anyone advocating a giant war) to transform the political dynamic is hoping for something essentially unprecedented.