Meh...most economics believe the union wage premium exists. It's anywhere from 3-20% and dependent on industry (one example: public school v. private school teacher wages based on years of experience). Closed shops are able to extract more (by exercising monopoly power) than union shops than open shops than non union shops. It's large in the public sector than the private because of regulatory capture. You can't avoid the supply curve, though, and the premium has to be made up elsewhere (....it must come from somewhere....if you take it from the capitalist overlords, which means lower profits which means lower investments in said industry). The union wage premium, though, has dropped for a lot of industries subject to non-union international competition....in said cases the unions just wind up pricing themselves out in the US to lower cost overseas firms. It's one of the theories for why unions have declined in goods creation industries, but are robust in services and public sector industries. TANSTAAFL and there are costs for every intervention a government makes.