Rummaging around through Mark Thoma's archives, I noticed he had a nice post last week laying out various possible reasons for the decline of union membership in the United States since the 1970s. Explanations include the idea that workers are relatively well-off today, thereby lessening the demand for unions; the fact that globalization has destroyed labor's bargaining power; the massive downsizing in manufacturing over the past thirty years; staunch employer opposition to organizing; and of course, laws and government policies that are, by and large, hostile towards unionization.

Now some economists have tried to assign relative weights to each, and smart people can argue about this list all day. (Globalization, for instance, seems like a poor explanation given that the United States is actually less exposed to trade than smaller yet still highly-unionized countries such as the Netherlands.) But set that aside. Asking why unions have declined over the last thirty years is sort of the wrong question. All monopolies tend to decline over time. The growth of unions, rather than their stagnation, is the striking fact that, I think, really demands explanation.

It doesn't get much attention, but there are only a few select points in American history in which union density actually rocketed upward. Unions multiplied and prospered during both world wars because the government helped organize the "war industries" in exchange for no-strike pledges. And during both the Progressive and Depression periods, union density grew largely because upstart radical unions—the IWW during the 1910s, factions of the CIO during the 1930s—challenged the AFL's primacy. (In many cases, union density expanded because employers chose to negotiate with the collaborationist AFL—or let the AFL charter company unions—in order to head off attacks by the more radical unions.)

And that's pretty much it. After 1945, the CIO's postwar organizing strategy—focusing on public employment, retail, and southern industries—fell victim to the anti-union Taft-Hartley bill that passed through Congress, the demise of Operation Dixie at the hands of southern racism, and labor infighting that led to a Cold War purge of left-leaning unions. Eventually the CIO merged with the AFL and private sector union density has withered ever since, as the federation has acted as a monopoly more interested in gains for its own members—and understandably so—than expanding union density. (Public sector unions, on the other hand, have had more success.)

Two proposed solutions for labor's decline have been put forward in the present day. In Congress, Rep. George Miller (D-CA) has introduced the Employee Free Choice Act, which would legalize card checks (making it easier for employees to vote themselves into a union), speed up the union certification process, and increase penalties for employers who violate labor law. Among labor leaders themselves, Andy Stern and the Change to Win breakaway faction of the AFL-CIO have pledged to spend more money on organizing rather than politics.

Both ideas sound promising, but in reality will probably have limited effect. Unions use different estimates, but a decent rule of thumb is that it costs about $2,000 to organize a new member. Adding one million new members would cost $2 billion—or about 30 percent of the AFL-CIO's total member dues prior to the split. One million new members is nothing to sneeze at, but it would also add merely a point to total union density in the United States—hardly enough to make a dent in labor's long decline. (I also agree with Robert Fitch that some of Stern's specific organizing tactics—such as making political contributions to convince governors to add home-care workers to the SEIU's rolls—have had only mixed results.)

At any rate, I'll probably write more on this later, because I need to get to work. Basically, I do think unions need to make a serious comeback in the United States—for many of the reasons outlined by Nathan Newman here. But history suggests that it will take more than modest improvements in both organizing strategy and congressional legislation to achieve the same dramatic upsurge in union density that took place during the Progressive era and the 1930s. What it will take is, I think, an extremely difficult question.