While charter schools are among the most prevalent public-private partnerships in the education sector, they are frequently only assessed by measuring outputs such as enrollment and test scores. In contrast, this article assesses the logic model behind charter schools, specifically the mechanisms of accountability and competition, through a study of the Concession Schools in Bogotá, Colombia, using a realist evaluation methodology. Despite the program's success in increasing access in marginalized areas, findings indicate that accountability and competition were hindered in practice-because of insufficient choice for parents and other unique organizational and Education Policy Analysis Archives Vol. 25 No. 10 2 political factors. For example, particular issues emerged that influenced the availability of viable charter operators to open and manage schools while political orientations, political shifts, and evaluation design issues affected the charter authorizer's ability to monitor, assess, and hold charters accountable. Successfully operationalizing public-private partnerships requires that the mechanisms underlying each link in the policy theory are carefully designed and supported, that they directly connect, and that the functioning of one does not adversely impact the others-a difficult task given the dynamic and sensitive nature of such mechanisms and the imperfect world of educational reform. The article concludes by reflecting on a number of issues, including charter school exit from the market, the need for accountability of charter authorizers themselves, the increasing political clout of charter management organizations and their allies, and the ways that these actors circumvent or avoid public accountability. Keywords: charter schools; Colombia; public-private partnerships; accountability; competition; charter authorizers Asociaciones público-privadas, rendición de cuentas y competencia: Teoría versus realidad en las escuelas chárter de Bogotá, Colombia Resumen: Si bien las escuelas chárter se encuentran entre las asociaciones público-privadas más relevantes en el sector educativo, con frecuencia sólo son evaluadas por sus indicadores de cobertura/matrícula y por los resultados de las pruebas. Tomando distancia de esta tendencia, este artículo evalúa los componentes del modelo que hay detrás de las escuelas chárter y, específicamente, se enfoca en los mecanismos de rendición de cuentas y competencia, en un estudio de caso sobre las Escuelas por Concesión en Bogotá, Colombia, utilizando una metodología de evaluación realista. A pesar del éxito del programa al permitir el aumento en el acceso a la escuela en áreas marginadas, los hallazgos indican que la rendición de cuentas y la competencia se vieron restringidas en la práctica debido a la escasa posibilidad que tienen los padres para elegir y a otros factores particulares de índole política y organizativa. Por ejemplo, surgieron problemas específicos que influyeron en la disponibilidad de agentes idóneos que pudieran asumir la apertura y ad...
