Governments frequently introduce education policy reforms to improve the educational outcomes of pupils. These often have simultaneous effects on pupils because they are implemented in the same schools and at the same time. In this paper, we evaluate the relative and multiple overlapping effects of two flagship British educational policies--the Excellence in Cities initiative and the specialist schools policy. We compare the estimates from multi-level cross-sectional and difference-in-differences (DID) matching models. The policy impacts estimated from cross-sectional models are typically positive, quite large and rise over time. The specialist schools policy had a much greater impact on test scores. However, DID matching estimates of the overlapping policies show an increase in GCSE test scores by only 0.5-1 point. We interpret this result as a small causal effect arising from complementarities between the two policies. (Contains 6 tables, 3 figures and 16 notes.)