Quoted: Douglas Harris, an economist at the University of Wisconsin, found that when more than half the students were low-income, only 1.1 percent of schools consistently performed at a â??highâ? level (defined as two years of scores in the top third of the U.S. Department of Educationâ??s national achievement database in two grades and in two subjects: English and math). By contrast, 24.2 percent of schools that are majority middle-class met Harrisâ??s standard.