The possible experts: how epistemic communities negotiate barriers to knowledge use in ecosystems services policy

The increased salience of how to value ecosystems services has driven up the demand for policy-relevant knowledge. It is clear that advice by epistemic communities can show up in policy outcomes, yet little systematic analysis exists prescribing how this can actually be achieved. This paper draws on four decades of knowledge utilisation research to propose four types of `possible expert' who might be influential on ecosystems services. Broad findings of a literature review on knowledge use in public policy are reported, and the four-fold conceptualisation pioneered by Carol Weiss that defines the literature is outlined. The field is then systematised by placing these four modes of knowledge use within an explanatory typology of policy learning. With how, when, and why experts and their knowledge are likely to show up in policy outcomes established, the paper then proposes the boundaries of the possible in how the ecosystems services epistemic community might navigate the challenges associated with each learning mode. Four possible experts emerge: with political antenna and epistemic humility; with the ability to speak locally and early to the hearts and minds of citizens; with a willingness to advocate policy; and, finally, with an enhanced institutional awareness and peripheral policy vision. The paper concludes with a brief discussion of the utility of the analysis.