Starting in the 1960s, the United States government embarked on a new approach to providing rental housing to low-income people. Federal policy shifted from public housing to public-private arrangements in which private companies, both nonprofit and for-profit enterprises would build and manage social welfare housing. The public-private housing programs created in the 1960s and 1970s were highly productive but many of the housing projects, buffeted by bad underwriting, weak management, and economic hard times, deteriorated badly. In response housing advocates produced programs and procedures to rescue troubled projects by buttressing their finances or conveying them to responsible parties.