title: Effect of risk aversion on prioritizing conservation projects.
abstract: Conservation outcomes are uncertain. Agencies making decisions about what threat mitigation actions to take to save which species frequently face the dilemma of whether to invest in actions with high probability of success and guaranteed benefits or to choose projects with a greater risk of failure that might provide higher benefits if they succeed. The answer to this dilemma lies in the decision maker's aversion to risk--their unwillingness to accept uncertain outcomes. Little guidance exists on how risk preferences affect conservation investment priorities. Using a prioritization approach based on cost effectiveness, we compared 2 approaches: a conservative probability threshold approach that excludes investment in projects with a risk of management failure greater than a fixed level, and a variance-discounting heuristic used in economics that explicitly accounts for risk tolerance and the probabilities of management success and failure. We applied both approaches to prioritizing projects for 700 of New Zealand's threatened species across 8303 management actions. Both decision makers' risk tolerance and our choice of approach to dealing with risk preferences drove the prioritization solution (i.e., the species selected for management). Use of a probability threshold minimized uncertainty, but more expensive projects were selected than with variance discounting, which maximized expected benefits by selecting the management of species with higher extinction risk and higher conservation value. Explicitly incorporating risk preferences within the decision making process reduced the number of species expected to be safe from extinction because lower risk tolerance resulted in more species being excluded from management, but the approach allowed decision makers to choose a level of acceptable risk that fit with their ability to accommodate failure. We argue for transparency in risk tolerance and recommend that decision makers accept risk in an adaptive management framework to maximize benefits and avoid potential extinctions due to inefficient allocation of limited resources.
authors.affiliation: ARC Centre of Excellence for Environmental Decisions, the NERP Environmental Decisions Hub, Centre for Biodiversity & Conservation Science, University of Queensland, Brisbane, Queensland, 4072, Australia. a.tulloch@uq.edu.au.
authors.forename: Ayesha I T
authors.initials: AI
authors.lastname: Tulloch
authors.forename: Richard F
authors.initials: RF
authors.lastname: Maloney
authors.forename: Liana N
authors.initials: LN
authors.lastname: Joseph
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Bennett
authors.forename: Martina M I
authors.initials: MM
authors.lastname: Di Fonzo
authors.forename: William J M
authors.initials: WJ
authors.lastname: Probert
authors.forename: Shaun M
authors.initials: SM
authors.lastname: O'Connor
authors.forename: Jodie P
authors.initials: JP
authors.lastname: Densem
authors.forename: Hugh P
authors.initials: HP
authors.lastname: Possingham
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources / Q000191:economics* / Q000331:legislation & jurisprudence / Q000379:methods*; D003362:Cost-Benefit Analysis; D003657:Decision Making; D007448:Invertebrates; D009520:New Zealand; D010944:Plants; D012306:Risk; D035501:Uncertainty; D014714:Vertebrates
keywords: Project Prioritization Protocol; Protocolo de Priorización de Proyectos; análisis de rentabilidad; análisis de riesgo; conservation decision making; cost-effectiveness analysis; efectividad de manejo; especies amenazadas; incertidumbre; management effectiveness; risk analysis; risk tolerance; threatened species; tolerancia de riesgo; toma de decisiones de conservación; uncertainty