Market reforms in education are part of the educational policy landscape in many countries. Central to arguments for market reforms is the idea that competition and choice will spur changes in schools to be more innovative, which in turn will lead to better student outcomes. We define innovation in terms of a practice's relative prevalence in a local district context. A charter school is innovative in its use of a practice if the traditional public schools in its local school district are not using that practice. We explore factors based on arguments for charter schools that may affect a charter schools' propensity toward innovation to explain variation in levels of innovation across charter schools. We find that, on the whole, charter schools do not fulfill their promise of innovation. Teacher tenure is the most notable exception. Parental involvement is the only characteristic of charter schools that significantly predicts variation in levels of organizational innovativeness. (Contains 5 tables.)