vdem_vci_hci {demcon}R Documentation

Vertical and Horizontal Constraints Indices


A dataset of country-year vertical and horizontal constraints as calculated by Fjelde et al. 2021.




A data frame with 15040 rows and 6 variables:


The common country name.


The Gleditsch and Ward numeric country code.


The Correlates of War numeric country code.


The year of valid CoW observations.


The horizontal constraint index.


The vertical constrain index.



Data Source

The horizontal and vertical constraints metrics in this dataset were developed by Fjelde et al. (2021) in:

Fjelde, H., Knutsen, C. H. & Nygård, H. M. Which Institutions Matter? Re-Considering the Democratic Civil Peace. International Studies Quarterly 65, 223–237 (2021), doi:10.1093/isq/sqaa076.

Dataset is available in the supplementary materials Replication Package

The Indices

Horizontal constraints (HCI) represent checks and balances on centralized executive power. These include constraints put in place by executive and judicial branches of government. Horizontal constraints mainly serve the interests of non-governmental elites by protecting their interests against an uncontrolled executive.

This is in contrast to vertical constraints (VCI), which represent civil liberties attributed to the general populace that constrain executive actions. These include suffrage, the presence of elections that appoint executive officials, freedom of association, freedom of expression, and the presence of clean and fair elections.


Both indices were developed from existing variables in the greater V-Dem data. Although HCI represents a simple arithmetic mean (see hci()) of V-Dem's legislative constraints (v2xlg_legcon) and judicial constraints variables (v2x_jucon), the methods behind the VCI are more complicated.

At it's core, VCI is a multiplicative aggregation of 5 V-Dem variables designed to measure suffrage, elected officials, freedom of association, freedom of expression and clean elections, (v2x_suffr, v2x_accex, v2x_frassoc_thick, v2x_freexp_thick, v2xel_frefair). However, the final component (v2xel_frefair) is a composite index developed with a Bayesian factor analysis of 8 other V-Dem indicators (v2elembaut, v2elembcap, v2elrgstry, v2elvotbuy, v2elirreg, v2elintim, v2elpeace, v2elfrfair), of which, the authors adapted by purging 2 of the components representing government intimidation or violent actions (v2elintim, v2elpeace) to prevent potential endogeneity in their regressions for the onset of conflict; i.e. you don't want to predict the onset of conflict with and independent variable that is, in-part, composed of measures of conflict.

Although the original v2xel_frefair composite index was developed using V-Dem's Bayesian Factor Measurement Model, the VCI adapted for this study took a simpler approach. In footnote 12, the authors state that the modified composite index was created by averaging the 6 non-violent indicators of v2xel_frefair (v2elembaut, v2elembcap, v2elrgstry, v2elvotbuy, v2elirreg, v2elfrfair). Although not explicitly stated, it's presumed that the average for these 6 indicators was converted to a 0-1 scale using "...the cumulative distribution function of the normal distribution". This is the standard V-Dem procedure for their 0-1 interval indices as stated on page 7 of the V-Dem V11.1 Methodology handbook.

Lastly, the VCI constructed for this manuscript was carried out using the V-Dem 7.1 dataset. Since that time (current version is V11.1), 2 of the indicators used in the VCI calculation have been renamed and slightly altered:

  1. v2x_freexp_thick was converted to v2x_freexp_altinf starting with version 11. The sub-components of this composite index were altered slightly, but they still encompass the same concepts of censorship in media.

  2. v2x_accex was renamed v2x_elecoff starting with version 8. This was due to changes in the aggregation method for calculating the composite index. Although the conceptual design for the composite indicator has not changed, the aggregation formula is more complex and consists of 20 indicators (opposed to 10 for the original v2x_accex).



See Also

hci(), vci()

[Package demcon version 0.3.0 Index]