Barro on Unions

Robert doesn't like them.  An excerpt:

There is evidence that right-to-work laws—or, more broadly, the pro-business policies offered by right-to-work states—matter for economic growth. In research published in 2000, economist Thomas Holmes of the University of Minnesota compared counties close to the border between states with and without right-to-work laws (thereby holding constant an array of factors related to geography and climate). He found that the cumulative growth of employment in manufacturing (the traditional area of union strength prior to the rise of public-employee unions) in the right-to-work states was 26 percentage points greater than that in the non-right-to-work states.