Arab political regimes are both unusually undemocratic and unusually stable. A series of statistical models are nested to parse competing explanations. The democratic deficit is comprehensible in terms of modernization, democracy waves, and the Arab population share, with the last determinant...

Long-lived undemocratic political regimes are ubiquitous in the Arab world. The likelihood of a transition declines as a country liberalizes and approaches the democratic asymptote. Worldwide democracy waves are positively associated with the likelihood of transition. Adherence to Islam among...