Less than 11% of pupils attending public schools are entitled to a full teaching day, compared with 46% for those attending private schools (Barrera et al., Since private schools cover predominantly pupils from well-off families (and more so in Colombia than in many other countries, OECD, 2012c), many pupils face a double liability of coming from a disadvantaged background and attending a lower-quality school. Second, the poor selection and training of teachers affect education quality.