Under federal law enacted in the 1990s, a limited number of public housing agencies (PHAs) have received demonstration authority under which they may experiment with alternatives to the standard rules under which the Housing Choice Voucher and public housing programs operate. Some Moving to Work (MTW) agencies are permitted to merge the funding streams they receive from the U.S. Department of Housing and Urban Development and use them flexibly to provide housing and services to low income families and individuals. One of the criticisms of MTW is that performance measurement has been weak for PHAs operating under MTW authority.