(WASHINGTON) -- This week, Michigan became the 24th state in the country to adopt a right-to-work law. The passage of the bill by the state legislature, and eventual signing by Rick Snyder, the state's Republican governor, brought a huge wave of protests in a state with deep union roots.
Right-to-work laws have garnered a lot of national attention in recent years as more states have implemented this legislation that prohibits unions from requiring workers to pay dues as a condition of their employment. The laws are meant to regulate agreements between employers and labor unions that would prohibit the employer from hiring non-union workers.
The laws are particularly divisive -- proponents argue that businesses will be more likely to set up shop in the state, while opponents argue that weakening union power will lead to lower wages. Because each state has a variety of factors that must be considered individually when assessing its overall economic standing, it's difficult to fully assess the validity of each side's argument, since you can't isolate the direct effect of these laws on the state's economy.
However, a study conducted in 2007 by Lonnie Stevans of Hofstra University suggested that both sides of the argument are, to some degree, accurate.
"Findings are that the number of businesses and self-employed are greater on average in right-to-work states, but employment, wages, and per-capita personal income are all lower on average in right-to-work states," Stevans wrote.
But he noted that there was little "trickle down" from the business owners to the workers -- the laws benefitted the business owners who did not have to contend with union contracts, but business employees didn't get those same positive effects -- as evidenced by the lower salaries on average.
An analysis by ABC News of the most recent seasonally adjusted unemployment rates in states with right-to-work laws vs. those without such laws found that, on average, the unemployment rate in states with right-to-work laws was slightly lower than those without.
The average unemployment rate in the 24 states with right-to-work laws was 7 percent, while the average rate in the 26 states plus D.C. that do not have right-to-work laws was just under 7.6 percent -- a difference of just under .6 percent.
The state with the lowest unemployment rate in the country, Nebraska at just 3.8 percent unemployment, has such a law in place, as does the state with the highest unemployment rate, Nevada at 11.5 percent.
Support for the laws has often tended to fall along party lines, with Democrats opposing and Republicans supporting. The vast majority of states with right-to-work laws are Republican led, the majority of states without are led by Democrats.
Below is the list of the 24 states with right-to-work laws:
- North Carolina
- North Dakota
- South Carolina
- South Dakota
Copyright 2012 ABC News Radio