Scholars are divided on the merits of ethnofederalism as an institutional approach to the management of ethnically divided societies. For some, ethnofederalism is a potentially workable compromise between the demands for independence of territorially concentrated ethnic groups and the desire of a common state to preserve its territorial integrity; for critics, it is a short-cut to secession and ultimate state collapse. The argument of critics is theoretically plausible, but an examination of the universe of post-1945 states with ethnofederal arrangements, both failures and successes, shows that ethnofederalism has succeeded more often than it has failed. Within this universe of cases, moreover, ethnofederalism has demonstrably outperformed institutional alternatives, and where ethnofederal systems have failed, they have failed where no institutional alternatives could plausibly have succeeded. The increasing enthusiasm among policymakers and practitioners for prescribing federal solutions to ethnic problems is both understandable and defensible in light of these findings.