title: When do financial incentives reduce intrinsic motivation? comparing behaviors studied in psychological and economic literatures.
abstract: OBJECTIVE
  To review existing evidence on the potential of incentives to undermine or "crowd out" intrinsic motivation, in order to establish whether and when it predicts financial incentives to crowd out motivation for health-related behaviors.
  
  
  METHODS
  We conducted a conceptual analysis to compare definitions and operationalizations of the effect, and reviewed existing evidence to identify potential moderators of the effect.
  
  
  RESULTS
  In the psychological literature, we find strong evidence for an undermining effect of tangible rewards on intrinsic motivation for simple tasks when motivation manifest in behavior is initially high. In the economic literature, evidence for undermining effects exists for a broader variety of behaviors, in settings that involve a conflict of interest between parties. By contrast, for health related behaviors, baseline levels of incentivized behaviors are usually low, and only a subset involve an interpersonal conflict of interest. Correspondingly, we find no evidence for crowding out of incentivized health behaviors.
  
  
  CONCLUSIONS
  The existing evidence does not warrant a priori predictions that an undermining effect would be found for health-related behaviors. Health-related behaviors and incentives schemes differ greatly in moderating characteristics, which should be the focus of future research.
authors.affiliation: Centre for the Study of Incentives in Health and Department of Psychology, King’s College London, United Kingdom. marianne.promberger@kcl.ac.uk
authors.forename: Marianne
authors.initials: M
authors.lastname: Promberger
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Marteau
mesh_terms: D060909:Economics, Behavioral; D015438:Health Behavior; D006801:Humans; D009042:Motivation; D011582:Psychological Theory