Professor of Transport in the School of Civil Engineering and Geosciences, Newcastle University.
The effect of informational and normative conformity in the preference for electric vehicles
Thursday 15th December 2016
According to Crutchfield (1955) individuals consciously or unconsciously tend to “yield to group pressures” and consequently to act in agreement to the majority position. Social conformity has been extensively studied in psychology with also several applications to transport problems. Field experiments are typically used to evaluate the impact of social influence on self-reported changes toward environmentally sustainable transport behaviours. In this seminar, I discuss various aspects of social conformity and the challenge of measuring informational and normative conformity effects in stated preference experiments. Differently from most of the literature in the field, measures of conformity are included as attributes inside a stated choice (SC) experiment, allowing a direct comparison of their effects with typical effects such as purchase price, range and fuel/electricity price. The impact of conformity in terms of policy implication is also discussed. The choice of electric vehicles (EV) is used as an illustrative example. Results from the estimation of hybrid choice models, show that all social conformity effects tested are highly significant and in particular the negative experience of other people has a powerful effect on individual preferences. The relative impact of social conformity effects in the overall utility can be high enough to compensate quite low driving range for EV or significant differences in purchase price (for example 1/3 higher for EV than ICV). Results also confirm that individuals’ behaviour is affected by the image they want other people to have of them, and being watched triggers a propensity to change reducing the inertia to stick with the current type of vehicle.