While recent research has shown that management matters, we know very little about the role of national contexts in shaping management effects on performance. We address this issue by comparing the impact of management of similar organizations—schools—in very different national contexts, the unitary and corporatist Denmark and the fragmented, adversarial Texas. We hypothesize that external as well as internal management matter more in Texas than Denmark. This is because Texas principals can gain power by negotiating the adversarial system, while the corporatist influence of teachers reduces the decision authority of principals in Denmark through collective agreements and important shop stewards. Based on combinations of parallel surveys of school principals and archival data on student performance, we confirm that aspects of both external and internal management matter substantially in Texas while having virtually no effect in Denmark. We therefore suggest that public management research should pay more attention to the role of context.