International Hierarchy Expert Survey

This is project page of the International Hierarchy and Functional Differentiation of States dataset, which is based on the International Hierarchy Expert Survey (IHES) conducted annually starting from 2022. As of September 2025, data for Waves I-IV is published. Wave V is expected to start in December 2025 – January 2026. Methodology of data collection and analysis is provided in the academic article published after the First Wave of IHES: https://doi.org/10.24833/2071-8160-2022-olf2. Please cite this academic paper, when using this dataset in your research.