In search of better predictors of new product adoption: three essays on the key determinants, predictive ability and temporal stability of behavioural expectations MahardikaHarryadin 2017 Predicting the adoption of new products has long been a priority for researchers and managers alike. Scholars and marketers are continually seeking better and more stable immediate predictors of consumers’ adoption of new products. This dissertation aims to explain the efficacy of behavioural expectations as a viable alternative predictor of behaviour than the more established behavioural intentions. Specifically, this dissertation offers a conceptual and empirical explanation for why behavioural expectation is potentially a better predictor than behavioural intention in terms of adoption of a new product. The explanations are presented in three related essays. The first essay examines, from a conceptual perspective, the role of behavioural expectations as a potentially superior predictor of behavioural intentions when the targeted behaviour is subject to impediments. A meta-analysis is conducted to demonstrate that behavioural expectation potentially has greater temporal stability and superior predictive ability than does behavioural intention. However, this determination ultimately depends on the antecedents, the key determinants, germane to the adoption process of the particular new technology under examination. To increase the generalizability of this thesis, the second essay is an empirical examination of the temporal stability and the predictive ability of behavioural expectations versus behavioural intentions in the context of pro-environmental marketing. It seeks to explain whether differences in the way in which consumers’ behavioural expectations versus behavioural intentions judgments are measured, discourage the adoption of new pro-environmental products and changes in pro-environmental behaviour. Three online experiments were conducted, including a longitudinal online experiment on pro-environmental donation behaviour. Findings confirm that behavioural expectation has a higher temporal stability than behavioural intention, potentially accounting for the greater predictive ability of the former. One key reason for this finding is that subjects may over-estimate their intention to act when responding to questions regarding behavioural intention. Finally, the third essay considers the extent of the predictive ability of behavioural expectations versus behavioural intentions in terms of the adoption/use of new technology subject to impediments. An online longitudinal experiment was designed to examine the sources and effects of two possible impediments to the adoption/use of new technology: experience (internal impediments) and facilitating conditions (external impediments). Findings indicate that behavioural expectations have a greater predictive ability than do behavioural intentions when subjects encounter impediments to adopting/using the new technology, particularly when experience and facilitating conditions are poor. The main reason was the tendency of subjects who responded to behavioural intentions measures to overestimate their control over the (internal) impediments, and to make underestimations when they think they have less control over the (external) impediments. Moreover, it is found that subjects who responded to behavioural expectations measures have a stronger Adoption-Use correlation compared to subjects who responded to BI measures regardless of the type of impediments that they had encountered. Taken together, the three essays advance extant knowledge of the debate between behavioural intention and behavioural expectation by proposing its key determinants, comparing its temporal stability and examining its predictive ability. Specifically, findings from this study suggest that behavioural expectation is a better predictor of behaviour that is subject to impediments, and also it is found to have superior temporal stability than behavioural intention. Based on aforementioned results, this study recommends scholars and marketers to consider behavioural expectation to be incorporated as immediate predictor of behaviour (i.e. adoption of new product) to extend various theoretical models, such as the Theory of Reasoned Action, Theory of Planned Behaviour and Technology Acceptance Model.