Motivation crowding by economic incentives in conservation policy: A review of the empirical evidence

The paper seeks to advance our understanding of the extent to which the use of economic incentives can undermine (crowd out) or reinforce (crowd in) people's intrinsic motivations to engage in biodiversity and ecosystem conservation. We first synthesize and classify the psychological mechanisms behind motivation crowding effects. Then we conduct a systematic review of empirical studies that test for motivation crowding effects triggered by economic incentives to encourage nature conservation. Based on eighteen empirical studies, we identify evidence of motivation crowding out and, to a lesser extent, crowding in effects. Finally, we discuss the implications for environmental policy and research. We note that the limited comparability of results across studies, the lack of baseline information about pre-existing intrinsic motivations, and a complexity stemming from cultural and contextual heterogeneity appear to be the main challenges when it comes to establishing more conclusive evidence. We conclude that, as economic instruments for conservation are increasingly being used worldwide, it is crucial to assess existing intrinsic motivations and expected changes in people's motivational structures prior to large-scale implementation. We call for caution with economic incentives in situations involving considerable uncertainty regarding the detrimental impacts on intrinsic motivation. (C) 2014 Elsevier B.V. All rights reserved.