This paper presents new evidence on the differences in quality and achievement of public, private, and charter schools by using the educational outcomes for the more than 1,200 schools of the Madrid region over the period 2005–2009. By applying an external test including three different areas, mathematics, writing, and language, the evolution of the achievement of the pupils in the three different types of schools, public, charter, and private, are analyzed.
Our results show that charter and, especially, private schools attain better results than public schools and are more responsive to its academic evolution, both at a lower cost. Private schools do their best to converge to the leading schools in their district in the previous year, whereas public schools do not seem to do so. This result holds even after controlling for the number of immigrants in the school, the age of the school, and its size. Also, the results seem quite robust, since we tested the relevance of different variables such as immigration, socioeconomic status, and foreign students and we obtained results that support our main hypothesis.