Not everyone agrees on how much money private firms save the government when they operate a prison or jail, but 10-15 percent is a reasonable estimate. When calculating how private firms manage to cut costs and still make a profit, the following aspects of their work are significant. Competition among the many private firms helps to ensure that the most efficient and most effective ones receive the most contracts. Private firms create savings with new management approaches, new monitoring techniques and administrative efficiencies. Innovative approaches allow them to build facilities faster, reduce labor costs, reduce tension between correctional officers and inmates, improve maintenance and make more efficient purchases. The existence of private prisons, and the threat of privatization, changes the incentives for government corrections officials. Not only can they learn directly from the practices of private operators, they often develop their own methods when faced with competition. That alone is a good argument for the existence of private prisons.