During the last 15 years, the public school system in Bogotá, Colombia has maintained a concession system in which 25 schools are managed privately with exemptions to many of the rules required in the traditional schools. This study uses the propensity score matching technique to examine whether students in the privately-managed schools have better scores on the Saber 11° examinations taken upon completion of secondary school. The results for 251 schools indicates that students with comparable socioeconomic characteristics score considerably better on these tests in the privately-managed schools than in the traditional public schools. Thus, there is evidence that the privately-managed public schools are a cost-effective alternative to the traditional public school.