Preferences as boundary condition of nudge effectiveness: The potential of nudges under empirical investigation

Nudges are changes to the environment in which people are presented with choice options to steer a person's decision to a particular ‘sensible’ choice, without restricting alternative options or changing financial incentives. Nudges were introduced as a behaviour-change tool that acknowledges that people have bounded rationality and therefore cannot be expected to always carefully deliberate all their decisions, despite their good intentions. However, nudge critics fear that people might be manipulated, because nudges make use of the subtle processes with which people interact with their environment. This dissertation contributes to this theoretical discussion with empirical research. We investigated to what extent people’s prior preferences influence the effectiveness of nudges to alter people’s choices. We studied whether behaviours such as, stand-up working, adding sugar to tea, portion-size selection for sodas and the selection/ rejection of meat products could be influenced by nudge interventions. The findings show that people’s preferences form an important boundary condition for the influence that a nudge has on an individual’s decision. When people have strong preferences for one of the alternative options a nudge will not be effective, importantly, when people have strong preferences for the desirable option the nudge becomes redundant. Taking peoples a priori preferences into account when designing and testing nudge interventions has been shown to be important. Empirical research demonstrated that nudges are neither the panacea nor a mass manipulation tool that some have portrayed them to be; instead, nudges are a behaviour-change tool that offers great potential within its boundary conditions