Replication Material for Paper: "Gomm and Quoß (2026): "How to Measure Environmental Concern: An IRT Evaluation and Advancement of Established Survey Scales. Environmental Politics. DOI: 10.1080/09644016.2026.2718610"

Replication code and Dataset for "How to Measure Environmental Concern: An IRT Evaluation and Advancement of Established Survey Scales"Measuring environmental concern is central to environmental public opinion research, yet the field lacks a comprehensive and consistent approach. Existing measures are limited by a lack of theoretical consensus, scarce validation, outdated wording, and, critically, limited precision at the upper end of the scale. We address these limitations by developing and validating a refined measure, defining environmental concern as people’s affective, cognitive, and conative positions toward human-induced problems and their willingness to solve them. Using Item Response Theory (IRT) on a large, representative Swiss sample (N = 7932), we assess 36 established survey questions to identify validated items with high measurement quality that reflect our core theoretical interest. We select the best-performing items and validate their power to predict pro-environmental behavior and policy support. We propose a new, precise combination of established survey items that significantly improves measurement at high levels of environmental concern and offer practical recommendations for survey researchers.