Polity Score Analysis
Also known as: Polity IV Analysis, Polity5 Analysis, Polity2 Score, Polity Index of Democracy and Autocracy
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.
Key highlights
- Exceptional historical and cross-national coverage (most states since 1800).
- Institution-focused coding gives a transparent, replicable regime measure.
- Separates democracy and autocracy components and combines them into a single familiar scale.
- Long the standard regime variable, enabling comparison across a vast literature.
Intuition
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How it works
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When to use it
Use Polity scores when you need a long-run, institution-based measure of regime type for classifying regimes, dating democratization and autocratization, or including regime type as a variable — for example in democratic-peace and dyadic conflict analysis. Its 1800-onward coverage is a major asset. It is less suited when you need fine-grained or multidimensional democracy measures (where V-Dem is richer), when the anocracy middle category is doing too much work, or when the executive-constraints emphasis omits dimensions central to your question.
Strengths & limitations
- Exceptional historical and cross-national coverage (most states since 1800).
- Institution-focused coding gives a transparent, replicable regime measure.
- Separates democracy and autocracy components and combines them into a single familiar scale.
- Long the standard regime variable, enabling comparison across a vast literature.
- The composite collapses distinct institutional dimensions into one number, hiding heterogeneity.
- The middle 'anocracy' range mixes very different regimes and can drive spurious findings.
- Coding involves judgment, and some components overlap with outcomes researchers study (e.g., conflict).
- Less granular and multidimensional than newer measures such as V-Dem.
Common pitfalls
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Applications
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Frequently asked
What is the difference between POLITY and POLITY2?
POLITY is the raw composite score (democracy minus autocracy), but it uses special non-numeric codes for periods of foreign occupation (−66), anarchy/interregnum (−77), and transition (−88). POLITY2 converts these into a continuous −10 to +10 series — treating interruptions as missing or interpolating across transitions — so it can be used directly in time-series and panel analysis. Using raw POLITY with the special codes as numbers is a common and serious error.
What is an 'anocracy' and why is it controversial?
Anocracies are mixed or incoherent regimes scoring in the middle of the Polity scale (roughly −5 to +5), combining democratic and autocratic features. The category is controversial because it lumps together very different regimes and because some of its component codes overlap with political instability and conflict, raising concerns that findings linking anocracy to civil war may be partly artifacts of how the measure is constructed.
How does Polity compare with V-Dem?
Polity offers a parsimonious, institution-based regime score with very long historical coverage. V-Dem provides a far more granular, multidimensional set of indices built from hundreds of indicators and expert ratings with measurement-uncertainty estimates. Polity is simpler and historically deep; V-Dem is richer and disaggregated. Many studies use Polity for long-run analyses and V-Dem when conceptual breadth or specific democracy dimensions matter.
Sources
- 1.Marshall, M. G., & Gurr, T. R. (2020). Polity5: Political Regime Characteristics and Transitions, 1800–2018 (Dataset Users' Manual). Vienna, VA: Center for Systemic Peace.
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Cite this page
ScholarGate. (2026, June 22). Polity Score Analysis. ScholarGate. https://scholargate.app/international-relations/polity-score-analysis