Hubby and I have been running a small business for the last several years providing various kinds of insurance services including premium audits. In auditing payroll for work comp and general liability audits, most companies keep separate records for union/government jobs and non-union/non-government jobs. The hourly wage, certain benefits, etc. are often artificially substantially higher for the union and government jobs. As it is easy to see in the separate records, the difference in fact is quite stunning.
As New Mexico has a lot of government work with its national labs, bases, and various other government installations, some of the contractors bid on and got job involving some of the stimulus money. They acknowledged that they payroll costs were a lot more for those jobs than for regular work, and they also charged considerably more for materials and processes to meet government specifications, and the job took significantly longer than it otherwise would. The government requires contractors, at least here. to be union or, if not union, to pay union scale.
Once the government job is completed, however, they go back to prevailing area wages, materials, processes, and materials.
Almost no new jobs were created even during the short term jobs. We the taxpayer just paid a whole lot more to get the government job done than we would if it had been done in the private sector. But that's the payoff to the Unions. Nobody will be allowed to compete against the Unions by underbidding union shops.