Many papers describe the Chilean voucher system as the "textbook" voucher case. But this is mistaken and has prevented research to undertake the key question of how the particular design of the Chilean voucher system determines the results obtained in Chile. This also prevents discussion of how a voucher system with a different design could lead to different results. The issue is that the Chilean voucher system is an incentive system that is more complicated to evaluate than is commonly believed. Hence different papers estimate different treatment effects, which answer different questions, as is explained in the paper. Summarizing, the Chilean voucher system has different sets of incentives both on the demand and on the supply side. On the supply side, the system does not necessarily eradicate bad schools, and those schools tend to attract poor students. From the demand side, the poorest students are unable to attract a high quality private school because the value of the voucher is too small (since voucher amounts-prices-are set lower than equilibrium). Hence, both due to problems in the supply and demand side, the system offers low quality to poor students. The incentives faced by municipal schools are different from what they are assumed to be in the "textbook" voucher system. Municipal schools do not face the choice between supplying an adequate quality of education or closing. Recognizing the lack of adequate incentives faced by public schools, the Ministry of Education in Chile has built a parallel system of incentives. This is a second deviation from the "textbook" case. Finally, the Ministry of Education in Chile strongly regulates private subsidized schools. In sum, what some view as the "textbook" voucher system is in reality a patchwork system of incentives and constraints. We discuss how this patchwork makes evaluation of the results harder and how different papers may answer different questions (and sometimes possibly the wrong questions). © Taylor & Francis Group, LLC.