Ofqual's report included evidence from research interviews with 100 representatives of schools affected by a drop in grades - and a group of head teachers had written to Ofqual requesting transcripts of these interviews.
Barbara Bruns, an economist at the World Bank who has written a book about Brazilian schools, praises the system, created over the past 15 years, of rating schools on how much students learn and how many of them drop out or repeat grades.
There is some evidence that parents of children at grade 6, 7 and 8 who are doing poorly on academic grades lose the financial support of parents and drop out of school.