A PLA is a collective pre-lease agreement with a union that sets the working conditions and contractual conditions before a project comes to an end. They aim to control costs, improve quality and ensure project completion without notice. Under the PLA, unions must control recruitment practices and non-unionized workers must accept union control. Executive Order 13502 encourages Denexecutive agencies to use PTAs in large-scale federally funded construction projects; However, executive agencies cannot discriminate against non-union contractors during the tendering process. Previous studies have also found increased costs when using PLA, including a 2000 study of a Nevada PLA water administration project, which determined that the project cost an additional $200,000 because the real weak supplier refused to sign the PLA. The project then went to a union contractor with a $200,000 increase in bid.  Also in 2000, a study was commissioned by Jefferson County, The New York Board of Legislators, which examined the possible use of a PLA for the Jefferson County Court complex, and concluded that a PLA could cost an additional $955,000. The estimated overall increase in project costs, if a LLP were to be used, would have been 7% of the total project cost.  The history of PLA in the United States began with several dam projects in the 1930s, including the Shasta Dam in California10 and the Hoover Dam in Nevada. However, PPPs remain controversial. A number of studies and reports have been published to determine the impact of APAs.
In addition to scientific research, reports have been prepared by government authorities and individuals on behalf of the national or federal government. In 1998, the Government Accountability Office prepared a report on PMMs, which highlighted an overall data deficit, but noted that „proponents and opponents of the use of PLAS said that it would be difficult to compare the performance of contractors in federal projects with and without LESIF, as it is very unlikely that two of these projects could be found , which were sufficiently similar in costs. Size, girth and timing. The GAO report concluded that it was difficult to draw „definitive conclusions“ about the impact of ALP on performance.  Recent reports include a 2009 positive study by the Cornell University School of Industrial and Labor Relations PTAs conducted since 2003 by the Beacon Hill Institute that concluded that PLAs increase project costs and an analysis published by the National University System Institute for Policy Research Analysis, which found that PLAs have increased the cost of schooling in California. Reports on legal considerations related to APAs clearly show that PTAs are an effective tool for labour relations.  In a 1999 report on the legality of AEPs, the authors stated that AEPs „serve as a productive and stabilizing force in the construction industry.“  This approach is supported by a UCLA study that questioned the results of the Beacon Hill Institute on PLA, which found that in the private sector, the use of ATPs „creates continuity and stability of the workforce in the workplace.“  Project work contracts (PLA) are one of many controversial issues in the construction industry.