The Wall Street Journal today has a piece [1] recognizing that Right to Work laws are among two vital public policies that:

"...stand out as perhaps the most important in attracting jobs and capital."

WSJ continues:

"States that permit workers to be compelled to join unions have much lower rates of employment growth than states that don't. Many companies say they will not even consider locating a factory in a state that does not have a right-to-work law."

Interestingly, as visible in the graph below, the bottom 10 economicly competitive states are all forced unionism states, while 9 of the top 10 are long time Right to Work states [2].