Validating Italian General Ecological Behaviour Questionnaire of Travellers using Dichotomous Rasch Model

Ecological behaviour and the impact on environment are subjects of public concern and understanding individual behavioural measures to induce sustainable lifestyles is of extreme importance for policy makers to assess and promote sustainable mobility. To this end, a questionnaire with highly reliable items, evaluation of determinants and accurate measurement of ecological behaviour is a precondition for understanding the levers for a behavioural change. This paper aims at understanding whether the dichotomous Rasch model provides a legitimate measurement of General Ecological Behaviour (GEB) using a 26 items questionnaire as a valid tool to assess pro-environment behaviour of a large sample of users. A web questionnaire was administered using the snowball sampling plan in the Piedmont region (Italy) reaching out a sample of 4473 respondents. Results suggest that using the dichotomous Rasch model, proposed questionnaire is able to effectively measure pro-environment behaviour of travellers. Unidimensionality, perfect level of item reliability of 1, very high item separation of 34.22, absence of larger differential item functioning, and local independence are all good indicators of a valid model. This research shows how a good, validated, and reliable measurement of ecological behaviour would support public bodies to plan environment focused transport policies thanks to the knowledge of which variables determine the pro-environment behaviour. In addition, the proposed approach allows also to measure the efficacy of the adopted policies.