Predators affect prey by killing them directly (lethal effects) and by inducing costly antipredator behaviours in living prey (risk effects). Risk effects can strongly influence prey populations and cascade through trophic systems. A prerequisite for assessing risk effects is characterizing the spatiotemporal variation in predation risk. Risk effects research has experienced rapid growth in the last several decades. However, preliminary assessments of the resultant literature suggest that researchers characterize predation risk using a variety of techniques. The implications of this methodological variation for inference and comparability among studies have not been well recognized or formally synthesized. We couple a literature survey with a hierarchical framework, developed from established theory, to quantify the methodological variation in characterizing risk using carnivore-ungulate systems as a case study. Via this process, we documented 244 metrics of risk from 141 studies falling into at least 13 distinct subcategories within three broader categories. Both empirical and theoretical work suggest risk and its effects on prey constitute a complex, multi-dimensional process with expressions varying by spatiotemporal scale. Our survey suggests this multi-scale complexity is reflected in the literature as a whole but often underappreciated in any given study, which complicates comparability among studies and leads to an overemphasis on documenting the presence of risk effects rather than their mechanisms or scale of influence. We suggest risk metrics be placed in a more concrete conceptual framework to clarify inference surrounding risk effects and their cascading effects throughout ecosystems. We recommend studies (i) take a multi-scale approach to characterizing risk; (ii) explicitly consider 'true' predation risk (probability of predation per unit time); and (iii) use risk metrics that facilitate comparison among studies and the evaluation of multiple competing hypotheses. Addressing the pressing questions in risk effects research, including how, to what extent and on what scale they occur, requires leveraging the advantages of the many methods available to characterize risk while minimizing the confusion caused by variability in their application.

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We develop and test a theoretical model that explains how collective psychological ownership—shared feelings of joint possession over something—emerges within new creative teams that were launched to advance one person’s (i.e., a creative lead’s) preconceived idea. Our model proposes that such teams face a unique challenge—an initial asymmetry in feelings of psychological ownership for the idea between the creative lead who conceived the idea and new team members who are beginning to work on the idea. We suggest that the creative lead can resolve this asymmetry and foster the emergence of collective psychological ownership by enacting two interpersonal behaviors—help seeking and territorial marking. These behaviors build collective ownership by facilitating the unifying centripetal force of team identification and preventing the divisive centrifugal force of team ownership conflict. Our model also proposes that collective ownership positively relates to the early success of new creative teams. The results of a quantitative study of 79 creative teams participating in an entrepreneurship competition provided general support for our predictions but also suggested refinements as to how a creative lead’s behavior influences team dynamics. The findings of a subsequent qualitative investigation of 27 teams participating in a university startup launch course shed additional light on how collective ownership emerges in new creative teams launched to advance one person’s idea.

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