Collective bargaining through unions gives its members market power in setting wages and for this reason was considered an antitrust violation. As time passed, unions were granted exemptions from antitrust laws by the Clayton Antitrust Act of 1914 and the National Labor Relations Act of 1935. Currently, 38 states allow union shops and 22 recognize the right to work.
Barro presents evidence that unions impede economic growth.
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.Barro predicts states that will witness battles over collective bargaining.
In general, the most likely arenas are states in which the governor and both houses of the state legislature are Republican (often because of the 2010 elections), and in which substantial rights for collective bargaining by public employees currently exist. This group includes Indiana, which has recently been as active as Wisconsin on labor issues; ironically, Indiana enacted a right-to-work law in 1957 but repealed it in 1965. Otherwise, my tentative list includes Michigan, Pennsylvania, Maine, Florida, Tennessee, Nebraska (with a nominally nonpartisan legislature), Kansas, Idaho, North Dakota and South Dakota.