Source
The horizontal constraints index specified in this function
were developed by Fjelde et al. (2021) in:
Fjelde, H., Knutsen, C. H. & Nygård, H. M. 2021. Which Institutions Matter?
Re-Considering the Democratic Civil Peace. International Studies
Quarterly 65, 223–237, tools:::Rd_expr_doi("10.1093/isq/sqaa076").
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.
The Horizontal Constraints Index represents a simple arithmetic mean (see of
V-Dem's legislative constraints (v2xlg_legcon) and judicial constraints
variables (v2x_jucon).