Polar Bear Population Forecasts: A Public-Policy Forecasting Audit Working Paper
Armstrong, J. Scott, Kesten C. Green, Willie Soon. 2008. Polar Bear Population Forecasts: A Public-Policy Forecasting Audit Working Paper Version 68: March 28, 2008
Full text [here]
Abstract: Calls to list polar bears as a threatened species under the U.S. Endangered Species Act are based on forecasts of substantial long-term declines in their population. Nine government reports were prepared to support the listing decision. We assessed these reports in light of evidence-based (scientific) forecasting principles. None referred to works on scientific forecasting methodology. Of the nine, Amstrup, Marcot and Douglas (2007) and Hunter et al. (2007) were the most relevant to the listing decision. Their forecasts were products of complex sets of assumptions. The first in both cases was the erroneous assumption that General Circulation Models provide valid forecasts of summer sea ice in the regions inhabited by polar bears. We nevertheless audited their conditional forecasts of what would happen to the polar bear population assuming, as the authors did, that the extent of summer sea ice would decrease substantially over the coming decades. We found that Amstrup et al. properly applied only 15% of relevant forecasting principles and Hunter et al. only 10%. We believe that their forecasts are unscientific and should therefore be of no consequence to decision makers. We recommend that all relevant principles be properly applied when important public policy decisions depend on accurate forecasts.
Key words: adaptation, bias, climate change, decision making, endangered species, expert opinion, extinction, evaluation, evidence-based principles, expert judgment, extinction, forecasting methods, global warming, habitat loss, mathematical models, scientific method, sea ice.
Dr. J. Scott Armstrong is professor of Marketing at The Wharton School, University of Pennsylvania. Professor Armstrong is internationally known for his pioneering work on forecasting methods. He is author of Long-Range Forecasting, the most frequently cited book on forecasting methods, and Principles of Forecasting, voted the “Favorite Book – First 25 Years” by researchers and practitioners associated with the International Institute of Forecasters. He is a co-founder of the Journal of Forecasting, the International Journal of Forecasting, the International Symposium on Forecasting, and forecastingprinciples.com [here]. He is a co-developer of new methods including rule-based forecasting, causal forces for extrapolation, simulated interaction, and structured analogies.
In 1989, a University of Maryland study ranked Professor Armstrong among the top 15 marketing professors in the U.S. In 1996, he was selected as one of the first six Honorary Fellows by the International Institute of Forecasters. He serves or has served on Editorial positions for the Journal of the Academy of Marketing Science, the Journal of Business Research, Interfaces and the International Journal of Forecasting , and other journals. He was awarded the Society for Marketing Advances Distinguished Scholar Award for 2000. One of the most frequently cited marketing professors worldwide, his “first-author” citation rate currently averages over 200 per year.
Dr. Kesten C. Green is Senior Research Fellow, Business and Economic Forecasting Unit, Monash University, Australia. He is Co-director of the Forecasting Principles site, forecastingprinciples.com [here], and a member of the Editorial Board, Foresight: The International Journal of Applied Forecasting and the Editorial Board, Forecasting Letters. He is also Founder and former Director of Infometrics Limited, a leading New Zealand economic forecasting and consulting house. He is also Founder and former Director of Bettor Informed, a computerised horse-racing information magazine based on assessment of probabilities under different conditions.
Dr. Willie Soon is a physicist at the Solar, Stellar, and Planetary Sciences Division of the Harvard-Smithsonian Center for Astrophysics and an astronomer at the Mount Wilson Observatory. Among his many published research studies is Reconstructing Climatic and Environmental Changes Of The Past 1000 Years: A Reappraisal with Sallie Baliunas, Craig Idso, Sherwood Idso, and David R. Legates. Energy & Environment, Vol. 14, Nos. 2 & 3, 2003.
