Failures in complex systems often emerge through gradual degradation and the propagation of stress across interacting components rather than through isolated shocks. Democratic systems exhibit similar dynamics, where weakening institutions can trigger cascading deterioration in related institutional structures. Traditional reliability and survival models typically estimate failure risk based on the current system state but do not explicitly capture how degradation propagates through institutional networks over time. This paper introduces a trajectory-aware reliability modeling framework based on Dynamic Causal Neural Autoregression (DCNAR). The framework first estimates a causal interaction structure among institutional indicators and then models their joint temporal evolution to generate forward trajectories of system states. Failure risk is defined as the probability that predicted trajectories cross predefined degradation thresholds within a fixed horizon. Using longitudinal institutional indicators, we compare DCNAR-based trajectory risk models with discrete-time hazard and Cox proportional hazards models. Results show that trajectory-aware modeling consistently outperforms Cox models and improves risk prediction for several propagation-driven institutional failures. These findings highlight the importance of modeling dynamic system interactions for reliability analysis and early detection of systemic degradation.

I contrast the regime successes and failures in Latin America and use them to develop and test a statistical model of democracy. This model builds on recent research into causal sequences driving democratization that help us understand the sources of the resilience or fragility of democratic regimes. I emphasize the "protective belt" of vibrant civil society, the rule of law, and institutionalized parties that work to stabilize political regimes. Here, however, I add three additional factors: polarization, populism, and anti-pluralist parties. I find that polarization and anti-pluralist parties are, as expected, harmful for electoral democracy. Populism, however, becomes harmful only when combined with anti-pluralism. The three components of the protective belt work together to maintain whatever level of democracy a country has, but the rule of law emerges as the most crucial component. This analysis incorporates insights from other work that emphasizes agency and proximate factors, to balance the more structural approach in the earlier work.

This document outlines the methodological considerations, choices, and procedures guiding the development of the Varieties of Democracy (V-Dem) project.

This document outlines the organisation and management of the V-Dem Project and the V-Dem Institute.

During the past decade, analyses drawing on several democracy measures have shown a global trend of democratic retrenchment. While these democracy measures use radically different methodologies, most partially or fully rely on subjective judgments to produce estimates of the level of democracy within states. Such projects continuously grapple with balancing conceptual coverage with the potential for bias (Munck and Verkuilen 2002; Przeworski et al. 2000). Little and Meng (L&M) (2023) reintroduce this debate, arguing that "objective" measures of democracy show little evidence of recent global democratic backsliding.1 By extension, they posit that time-varying expert bias drives the appearance of democratic retrenchment in measures that incorporate expert judgments. In this article, we engage with (1) broader debates on democracy measurement and democratic backsliding, and (2) L&M's specific data and conclusions.

This Codebook includes all the variables that V-Dem is compiling in the v14 dataset (2024).

This document lists (a) every country in the envisioned V-Dem database, (b) the numeric country code assigned to each coded country (in parentheses following the country name), (c) the identities of each polity that comprises a country's history; (d) the year coverage for which we have collected data or plan to collect data; and (e) the borders of each country, wherever this might be unclear.

Political scientists increasingly use crowdworkers to produce data, predominantly in the context of coding researcher-curated text or to retrieve simple data from the internet. In this article, we provide a theoretical and empirical basis for understanding when crowdworkers can provide data of sufficient quality to substitute for other types of coders. First, we introduce a typology of data-producing actors - experts, trained coders and crowds - and hypothesize factors that affect the substitutability of crowdworkers. We then examine how crowdworkers perform across coding tasks that vary along multiple dimensions of difficulty: information verifiability, availability and complexity. The results provide scope conditions bounding the substitutability of crowdworkers in political science applications. Although crowds can substitute for trained coders in the context of relatively simple information retrieval tasks, there is little evidence that crowdworkers can substitute for experts, whose tasks require both information retrieval and data synthesis.

In order to measure "democracy," the Varieties of Democracy project (V-Dem) developed an elaborate conceptual scheme with several distinctive characteristics. First, it favored concepts that ultimately would be measurable. Second, it sided clearly with the view that democracy is a continuum (or several continua) rather than a category such as a discrete regime type. Third, it differentiated among five "varieties" of democracy: electoral, liberal, participatory, egalitarian, and deliberative. This paper defines and contrasts each variety and provides a rationale for each one. It also explains why V-Dem abandoned Arend Lijphart's contrasts between consensus and majoritarian democracy. Second, V-Dem disaggregated each broad conception of democracy into more specific conceptual components, and the components into subcomponents, and so on, until reaching the most specific concepts that it considered feasible to measure. V-Dem's conceptual scheme has several consequences. One is that, because electoral democracy is an important component of the other four varieties, they all have much in common, although there are meaningful empirical differences, especially for egalitarian democracy. Another consequence is that the availability of disaggregated measures refocuses attention away from broad notions of "democracy," toward finer-grained, more distinct, and potentially more useful concepts such as freedom of expression, civil liberties, party competition, institutional checks on the executive, consultation, power asymmetries, and transparency.

This chapter develops and tests hypotheses about possible influences that lie outside national borders. There are many good reasons to expect that domestic factors are not the sole determinants. We lay out a theoretical framework that systematically catalogues most of the possible international hypotheses: exogenous shocks and endogenous networks such as those linking neighbors, allies, and colonizers and colonies. We then test selected hypotheses about exogenous shocks and contagion – the spread of democracy outcomes from country to country through various international networks. Surprisingly, contagion at first appears to be real but so small that it could be ignored when studying domestic influences. However, for some kinds of contagion our analysis implies that the long-run effects grow quite large and must be taken into account if we want to understand how democracies develop and decline. This paradox leads us to conclude that international influences are a hidden dimension of democratization.

This edited volume surveys and retests most of the central explanations for democracy outcomes (levels of electoral democracy and upturns and downturns in it) using Varieties of Democracy data. After a chapter describing historical trends, other chapters survey and test hypotheses concerning geography and demography; international influences; economic determinants; institutions; and social forces. The volume concludes with a new theoretical framework emphasizing the historical sequencing of different kinds of causes. The conclusion also uses path analysis to integrate the most promising hypotheses from the preceding chapters into causal sequences explaining levels, upturns, and downturns.

Part I sets forth the V-Dem conceptual scheme. Part II discusses the process of data collection. Part III describes the measurement model along with efforts to identify and correct errors.

In this paper we develop and test hypotheses about possible influences that lie outside national borders. A major reason for studying international influences is Galton’s Problem, which cautions that domestic determinants may receive too much credit for democratization if we ignore international determinants. There are many good theoretical and empirical reasons to expect that domestic factors are not the sole determinants. We lay out a theoretical framework that systematically catalogues most of the possible international hypotheses. We then test selected hypotheses about exogenous shocks and contagion – the spread of democracy outcomes from country to country through various international networks. We focus on contagion through neighboring countries, military alliances, and current and former colonial ties. Surprisingly, contagion at first appears to be real but so small that it could be ignored when studying domestic influences. However, for some kinds of contagion our analysis implies that the long-run effects grow quite large and must be taken into account if we want to understand how democracies develop and decline. For example, our estimates suggest that the average West European/North American country was about 0.20 points more democratic over the 1900-2010 period than it would have been without other democracies as neighbors. This paradox leads us to conclude that international influences are a hidden dimension of democratization.

This document includes a brief overview of the Varieties of Democracy (V-Dem) project – and the team behind the data.

Studies of a small number of countries have revealed that both democratic and nondemocratic subnational governments can exist within a single country. However, these works have neither demonstrated how common subnational regime variation is nor explained why some countries are more prone to it. This article does both. We show that subnational regime variation exists in all world regions, in both unitary and federal states, and in both the present and past, using Varieties of Democracy global data from 1900 to 2018. The article also demonstrates theoretically and empirically how social heterogeneity and factors undermining a national government's ability to extend control throughout a country promote this variation. Specifically, subnational regime variation is more common in countries that are ethnically diverse, rugged, and populous.

This Codebook includes all the variables that V-Dem is compiling in 2020 dataset.

This document lists (a) every country in the eventual V-Dem database, (b) the years for which we have collect data or plan to collect data (in parentheses next to the entry); (c) the polities that comprise each country’s 20th century history (even if falling outside the time-period that we wish to code); and (d) the borders of each country (wherever this might be unclear).

The V-Dem Dataset v11.1 covers 202 countries, with a year coverage: 1789-2020 483 V-Dem indicators, 82 indices and 5 high-level indices.