Greg Mankiw helpfully points to this entry in The Concise Encyclopedia of Economics written by Lawrence Summer, the director of the National Economic Council:
Another cause of long-term unemployment is unionization. High union wages that exceed the competitive market rate are likely to cause job losses in the unionized sector of the economy. Also, those who lose high-wage union jobs are often reluctant to accept alternative low-wage employment. Between 1970 and 1985, for example, a state with a 20 percent unionization rate, approximately the average for the fifty states and the District of Columbia, experienced an unemployment rate that was 1.2 percentage points higher than that of a hypothetical state that had no unions. To put this in perspective, 1.2 percentage points is about 60 percent of the increase in normal unemployment between 1970 and 1985.
Me: Of course, reunionization of America seems to be a key plan in Obama's plan to strengthen the middle-class. Know what would help the middle class? Faster economic growth. As I have written before:
The problem is a lack of sustained or even spectacular economic growth. Consider this: During the 1980s, the economy notched 19 quarters of 3.5 percent GDP growth or better. In the 1990s, the economy also notched 19 quarters of 3.5 percent growth or better. So far this decade? Just eight. Or look at the number of quarters of "hypergrowth," say, 5 percent or better. (This was JFK's GDP goal in the 1960s, by the way.) There were 12 in the '80s, eight in the '90s. So far this decade? Just a single quarter, the third quarter of 2003.