The rate of home ownership in the United States has grown to an unprecedented 67.7 percent since the 1990s. Low-income ownership has grown in particular. According to a study by researchers Mark Duda and Eric S. Belsky at Harvard University’s Joint Center for Housing Studies, an increase in manufactured housing has helped to fill the demand, especially in the South, where 40 percent of buyers purchased manufactured homes. In the Northeast and in central cities, apartment condos helped to meet the demand for home ownership.