On December 11, 2012, Michigan became the 24th state in the country to enact a “right to work law” — a controversial statute that prohibits employees from being forced to become dues paying members of a union as a condition of employment. Republican Gov. Rick Snyder signed the measure into law within hours of the bill’s passage, calling the statute “pro-worker and pro-Michigan.” With Michigan joining the ranks of other states with large union populations, such as Indiana, will other states soon follow? And what do newly passed right to work laws mean for the future of unions?

What is a “right to work law”?

Section 14(b) of the Taft–Hartley Act, known colloquially as the “right to work clause,” authorizes individual states (but not local governments) to adopt “open shop” rules whereby an employee cannot be compelled to join or pay the equivalent of dues to a union, nor can the employee be fired if he joins the union. The law allows states to outlaw the “union shop,” which requires all new employees to join the union after a minimum period after their hire. The law also gave states the power to outlaw agency shops, under which employees must pay the equivalent of union dues, but need not formally join the union. In other words, the Michigan law provides employees with the “the right to work” for a willing employer, regardless of whether or not they are a member or financial contributor to the union.

Proponents of right-to-work laws point to the Constitutional right to freedom of association, as well as the common-law principle of private ownership of property. They argue that workers should be free to join unions and/or to refrain from joining, and thus sometimes refer to non-right-to-work states as “forced unionism” states.

Opponents argue that right-to-work laws restrict freedom of association, and limit the sorts of “union security” agreements individuals acting collectively can make with their employer, by prohibiting workers and employers from agreeing to contracts that include “fair share fees.” They argue this creates a “free rider” problem because unless non-union employees pay fair share fees, they are benefiting from collective bargaining without paying union dues. Thus, the services provided to them by the union are being subsidized by paying union members, which can undermine the union.

The Michigan Law

By a narrow 58-51 vote, the Republican-led Michigan House passed a right to work bill that bans workplace rules making union membership a condition of employment for government workers. It then approved a second bill, covering private-sector workers, by a vote of 58-52. Like the other states that have adopted right to work laws, the new law bans closed shops that require union membership as a condition of employment. Both parts of the statute prohibit union security agreements, or agreements between labor unions and employers that govern the extent to which a union can require employees’ membership, payment of union dues, or fees as a condition of employment, either before or after hiring.

The laws will take effect 90 days after the end of the legislative session, which means they will probably become sometime in April 2013. Existing union contracts in Michigan will not be changed until they expire.

Will Other States Follow?

Some experts say that right to work laws in one state can have a domino effect in others, as neighboring states do not want to be seen as unfriendly or uncompetitive to employers. Robert Sikkel, a labor expert in Grand Rapids, Michigan, told CNBC.com that “Michigan is making this move because it saw Indiana do it. They’re afraid businesses may move to Indiana. Other states are going to look at this too to see if it’s best for them.”

With Michigan and Indiana adopting right to work laws in the past two years, the most likely candidate for considering such a law in the future is Ohio. Phillip Parker, president and chief executive officer of the Dayton, Ohio, Area Chamber of Commerce, said in a statement Tuesday that “When we are working with companies who want to investigate locations, the first question on their list is right to work.” A group called Ohioans for Workplace Freedom is gathering signatures to put the issue on the fall 2013 ballot.

Another state that could be soon to follow is Minnesota. Last year, Minnesota State Senator Dave Thompson introduced a constitutional amendment that would ban union and agency shops in the state. The amendment was slated to be on the November 2012 ballot, but the House voted to table the issue until the next term. Although the issue did not go to a vote in 2012, there is a high likelihood that it could garner further support after Michigan’s passage of the law.

A third candidate for a right to work law is Kentucky. The previous Republican governor, Ernie Fletcher, wanted to pass such a law, as did former Kentucky Senate President David Williams in his unsuccessful 2011 campaign against Democratic Gov. Steve Beshear. However, the Democratic-controlled House did not support the measure. Depending on how the 2014 elections turn, Kentucky could have a right to work law in the next five years.

Interestingly, Wisconsin, which had its own battle with unions last year when Gov. Scott Walker limited the collective bargaining powers of public employees (“Act 10”), does not appear to be a potential right to work state. At a “Talk with Walker” event at in Grand Chute, Wisconsin on December 11, 2012, Gov. Walker said he doesn’t believe right to work legislation such as that which recently passed in Michigan is a good idea for Wisconsin. Walker said he believed people were ready to move past the divisiveness of the Act 10 changes made in 2010 and that he thought trying to pass a right to work law would be a “huge distraction right now.”

Impact on Unions

According to the Bureau of Labor Statistics, only 11.8 percent of American workers (or nearly 14.8 million people) were union members in 2011. That number is down substantially from just a decade earlier, when 13.3 percent of workers (or 16.3 million people) were union members.

However, it should be noted that right to work laws do not outlaw unions and certainly will not make unions disappear. As Jordan Weissman, associate editor at The Atlantic wrote: “the reality is that local unions won’t be going cold turkey. The effects of right-to-work laws appear to unfold gradually and at the margins. Their dues paying members won’t vanish overnight. And if the spread of these statutes ultimately forces unions to make the case for themselves more effectively, it may go some ways toward restoring the public’s decayed trust in them.” Only time will tell whether right to work laws will become the norm throughout the country and what effect these laws will have on the union movement and labor and employment law in general.