University-educated women earn less than their male counterparts working in the same field, according to research from the American Association of University Women. A year after graduation, women earn only 80 per cent of what male graduates earn. A quarter of this gap is unexplained even after hours, parenthood and other factors are considered, the paper says. The AAUW said the discrepancy could be due to sex discrimination. The pay gap widens ten years after graduation, with women earning just 69 per cent of the income of their male colleagues.