方法对比

	V-Dem Democracy Measurement	Polity Score Analysis
领域	International Relations	International Relations
方法族	Process / pipeline	Process / pipeline
起源年份	2011	2020
提出者	V-Dem Institute (Michael Coppedge, John Gerring, Staffan Lindberg, et al.)	Ted Robert Gurr, Monty Marshall & Keith Jaggers (Center for Systemic Peace)
类型	Multidimensional, expert-coded measurement of democracy	Composite ordinal measure of regime authority characteristics
开创性文献	Coppedge, M., Gerring, J., Altman, D., Bernhard, M., Fish, S., Hicken, A., et al. (2011). Conceptualizing and measuring democracy: A new approach. Perspectives on Politics, 9(2), 247–267.	Marshall, M. G., & Gurr, T. R. (2020). Polity5: Political Regime Characteristics and Transitions, 1800–2018 (Dataset Users' Manual). Vienna, VA: Center for Systemic Peace.
别名	Varieties of Democracy, V-Dem Indices, V-Dem Democracy Indices, Disaggregated Democracy Measurement	Polity IV Analysis, Polity5 Analysis, Polity2 Score, Polity Index of Democracy and Autocracy
相关	3	3
摘要	Varieties of Democracy (V-Dem) is a measurement project that captures democracy as a multidimensional concept rather than a single score. Set out by Coppedge, Gerring, and colleagues (2011), V-Dem distinguishes five principles of democracy — electoral, liberal, participatory, deliberative, and egalitarian — and measures them from hundreds of specific indicators coded by multiple country experts. A statistical measurement model aggregates these expert ratings into disaggregated indicators and high-level indices, each accompanied by estimates of measurement uncertainty, producing one of the most detailed and transparent democracy datasets available.	Polity score analysis uses the Polity dataset to measure and compare the regime characteristics of states on a continuum from full autocracy to full democracy. Maintained by the Center for Systemic Peace (Marshall and Gurr), Polity codes institutional features — how chief executives are recruited, the constraints on their authority, and the openness of political competition — into separate democracy and autocracy indices that combine into a single polity score from −10 to +10. It is one of the most widely used measures of regime type in comparative politics and international relations.