[Excerpt] The National Labor Relations Act of 1935 (NLRA) gives most private sector workers the right to join or form a labor union and to bargain collectively over wages, hours, and working conditions. The act allows workers in the construction industry to enter into a collective bargaining agreement (CBA) before a project begins. A project labor agreement (PLA) is a collective bargaining agreement that applies to a specific construction project and lasts only for the duration of the project. In February 2009, President Barack Obama signed Executive Order 13502, which encourages federal agencies "to consider requiring" the use of PLAs on large-scale construction projects. Regulations implementing the Executive Order (EO) went into effect in May 2010.This report begins with a description of PLAs. It then describes President Obama's EO and summarizes regulations to implement it. The report then examines arguments for and against theuse of PLAs and reviews research on the economic effects of the agreements.