"Regrettably, CBO is unaware of any comprehensive information about the size of the federal government's contracted workforce," the agency wrote in the March 11 letter.
The CBO said there is no comprehensive, governmentwide data on the number of contracted employees paid by agencies or how much contractors make on average, and the data that exists is incomplete.
The Defense Department has started to collect data on the number of full-time positions funded by some of its service contracts, but not on its products contracts or facilities maintenance contracts, according to CBO.
The Defense Department's Inventory of Contracts for Services (ICS) reports that DoD spent $129 billion funding 670,000 full-time contractor employees, which would amount to $193,000 per contractor, according to the CBO.
But that calculation leaves out costs for machinery, equipment, capital costs and other non-salary issues, the agency said. But overall calculations between federal employee salaries and contractor salaries remains difficult, according to the CBO.
"Another reason that comparisons are difficult is that even if a contractor is performing a task similar to that performed by government employees, it may perform the task differently. For example, a contractor might hire a smaller but more experienced workforce to perform the task (or a larger but less experienced workforce); or the contractor might provide different facilities, equipment, working hours, or training to its employees," the CBO said.