In the wake of the Cold War democracy has gained the status of a mantra.1 However, no consensus has emerged about how to conceptualize and measure this key concept. For policymakers, activists, academics, and citizens around the wor ld the conceptualization and measurement of democracy matters. Billions of dollars in foreign aid spent every year for promoting democracy and governance in the developing world are contingent upon judgments about a polity's current status, its recent history, future prospects, and the likely causal effect of particular forms of assistance. A large body of social science work deals with these same issues. The needs of democracy promoters and social scientists are convergent. We all need better ways to measure democracy.The study of democracy and democratization lies at the center of political science and is increasingly important in economics, sociology, and history. In the post-Cold War world, democracy has also become a central foreign policy objective for many countries, and is often a critical condition for the distribution of international development assistance. The transition to democracy and its consolidation remain key issues in global development today. Yet, uncertainty persists over why some countries become and remain democratic and others do not (e.g. Acemoglu and Robinson 2006, Boix 2003, Houle 2009, Inglehart et al. 2005, Lindberg 2009, Lipset 1959, Paxton 2000, Przeworski et al. 2000, Teorell 2010). The recent literature provides a range of specific hypotheses that, while accompanied by relatively sophisticated empirical strategies for testing, reach few firm conclusions.One of the obstacles to advancement in the field of democratization studies is the absence of a wide-ranging database that tracks multifarious aspects of countries' institutional histories. Several democracy-measurement ventures cover only democracies (e.g. Lijphart 1999) or particular regions (e.g. Munck 2009, Lindberg 2006), or just one aspect such as elections (e.g. NELDA). Existing democra cy indic es that seek to measur e democr a cy tend to be problematic in several respects. This includes the BNR index developed by Bernhard, Nordstrom & Reenock (2001); the Bertelsmann Transformation Index (BTI) directed by the Bertelsmann Stiftung (various years); the Democracy Barometer developed by Wolfgang Merkel & associates (Buhlmann, Merkel, Muller & Wesels 2012); the BMR index developed by Boix, Miller & Rosato (2013), the Contestation and Inclusiveness indices developed by Coppedge, Alvarez, & Maldonado (2008); the Political Rights, Civil Liberty, Nations in Transit, and Countries at the Crossroads indices, all sponsored by Freedom House (freedomhouse.org); the Economist Intelligence Unit (2010) index ( EIU); t he Unif i ed Democracy Scor es (UDS) developed by Pemstein, Meserve, & Melton (2010); the Polity2 index from the Polity IV database (Marshall, Gurr, & Jaggers 2014); the democracy-dictatorship (DD) index develop ed by Ada m Przeworski & collea gues (Alva r ez, C heibub, Limongi, & Przeworski 1996; Cheibub, Gandhi, & Vr eela nd 2010); t he Lexical index of democracy developed by Skaaning, Gerring, & Bartusevicius (2015); the Competition and Participation indices developed by Tatu Vanhanen (2000); and the Voice and Accountability index developed as part of the Worldwide Governance Indicators (WGI) (Kaufmann, Kraay, & Mastruzzi 2010).To summarize the issues with this range of alternatives broadly for the sake of brevity: i) they focus primarily on the electoral dimension of democracy; ii) they are comprised of components not measured independently of each other; iii) except for Polity IV, they do not extend back far in time for a global sample of countries; iv) they are not transparent in design and replicable, hence the accuracy of the data is either unknown or unreported; v) they do not address potential problems of measurement error and vi) they cannot make fine distinctions across polities or through time in a reliable fashion (Treier & Jacka mn 2008; P emst ein et al. …