For decades, the policy of Michigan and other states without right-to-work laws has been to allow unions to negotiate for and collect mandatory union membership dues or agency fees from the workers they represent. This significant curtailment of workers' rights of free association has been tolerated because it is believed that unions must have a reliable stream of funds to represent workers effectively, and that it is unfair to allow individual workers to be "free-riders" who avoid bearing the costs of that representation. These assumptions are essential to understanding union objections to right-to-work; if unions do not need these funds, the moral case against free-riders loses whatever force it might otherwise have.
A review of LM-2 forms filed by various unions leaves much of that rationale in serious doubt. Based on the information in these reports, it is very likely that the typical Michigan union could function effectively as a worker representative on little more than half its current revenue by reducing political activism and prudently trimming excessive overhead and administrative costs.
Assuming Michigan were to enact a right-to-work law, empowering workers to withhold financial support from a workplace union, the effect on union revenue would probably be substantial. But unions would be unlikely to see a cut in revenues that approaches 50 percent. A revenue reduction of 10 to 25 percent would be far more likely. In right-to-work states, the vast majority of workers who are covered by collective bargaining agreements opt to join the union and pay regular dues. That percentage ranges from a high of 88.6 percent in Utah to a low of 77.4 percent in Mississippi. Adjusting to this sort of drop in income would be challenging for a union, but should not entail any loss in the quality of worker representation.
The case for continuing to force workers to financially support unions might have some weight if the typical union were a reasonably economical organization focused on worker representation, but the picture that emerges after examining union financial reports suggests that unions are anything but lean and focused. The typical union structure is weighed down by high overhead and administrative costs, and distracted by political activism.
We have generously granted unions privileges that we rarely give to other private organizations. Michigan unions appear to have been negligent about how they use these privileges and in some cases may have abused them. There appears to be no compelling reason for those privileges to be continued: Michigan unions do not really need all the money they have been given.
 Calculations based on the Union Membership and Coverage Database, using 2006 figures compiled by David Mcpherson and Barry Hirsch. Available online at http://www.trinity.edu/bhirsch/unionstats/.