Since the wounds from the recession started to clot about four years ago, the number of temporary workers in the economy has more than doubled. Today, temporary workers in the U.S. number about 17 million people. These numbers show a preference among employers for a dispensable workforce that can be expanded or contracted in a short time to meet demand. Others have upped temp numbers in an effort to circumvent a provision of healthcare reform that requires large employers to provide full time employees with coverage.
See "Temporary jobs becoming a permanent fixture", Christopher S. Rugaber, USA Today, July 9, 2013