We use a new sample of UK female identical twins to estimate economic returns to education. We use identical twins to control for family effects and ability bias (due to genes) and the education reported by the other twin to control for schooling measurement error. We also investigate the within-twin pair and within family correlations with observable correlates of ability. Our estimates suggest a return to schooling for females of about 7.7%. Contact address: Jonathan Haskel, Economics, QMW, Mile End Rd, London E1 4NS, England; [email protected], <www.qmw.ac.uk/~ugte153>. We thank the DfEE and the ESRC for financial support. We are of course solely responsible for the views, opinions and errors in this paper. 2 1