Accounting for Possibilities in Decision Making
Intended as a practical guide for decision analysts, this chapter provides an introduction to reasoning under great uncertainty. It seeks to incorporate standard methods of risk analysis in a broader argumentative framework by re-interpreting them as specific (consequentialist) arguments that may inform a policy debate—side by side along further (possibly non-consequentialist) arguments which standard economic analysis does not account for. The first part of the chapter reviews arguments that can be advanced in a policy debate despite deep uncertainty about policy outcomes, i.e. arguments which assume that uncertainties surrounding policy outcomes cannot be (probabilistically) quantified. The second part of the chapter discusses the epistemic challenge of reasoning under great uncertainty, which consists in identifying all possible outcomes of the alternative policy options. It is argued that our possibilistic foreknowledge should be cast in nuanced terms and that future surprises—triggered by major flaws in one’s possibilistic outlook—should be anticipated in policy deliberation.
KeywordsPossibility Epistemic possibility Real possibility Modal epistemology Ambiguity Ignorance Deep uncertainty Knightian uncertainty Probabilism Expected utility Worst case Maximin Precautinary principle Robust decision analysis Risk imposition Surprise Unknown unknowns
- Lempert, R. J., Popper, S. W., & Bankes, S. C. (2003a). Shaping the next one hundred years: New methods for quantitative, long-term policy analysis. Santa Monica: RAND.Google Scholar
- Resnik, M. D. (1987a). Choices: An introduction to decision theory. Minneapolis: University of Minnesota Press.Google Scholar
- Bernardo, J. M. (1979). Reference posterior distributions for Bayesian inference. Journal for the Royal Statistical Society. Series B (Methodological), 41, 113–147.Google Scholar
- Betz, G. (2011). Prediction. In I. C. Jarvie & J. Zamora-Bonilla (Eds.), The sage handbook of the philosophy of social sciences (pp. 647–664). Thousand Oaks: SAGE Publications.Google Scholar
- Blaizot, J-P., Iliopoulos, J., Madsen, J., Ross, G. G., Sonderegger, P., Specht, H. J. (2003). Study of potentially dangerous events during heavy-ion collisions at the LHC: Report of the LHC Safety Study Group. https://cds.cern.ch/record/613175/files/CERN-2003-001.pdf. Accessed 12 Aug 2015.
- Briggs, R. (2014). Normative theories of rational choice: Expected utility. The Stanford Encyclopedia of Philosophy. http://plato.stanford.edu/entries/rationality-normative-utility/.
- Church, J. A., Clark, P. U., Cazenave, A., Gregory, J. M., Jevrejeva, S., Levermann, A., Merrifield, M. A., et al. (2013). Sea level change. In T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex, & P. M. Midgley (Eds.), Climate change 2013: The physical science basis contribution of Working Group I to the fifth assessment report of the Intergovernmental Panel on Climate Change (pp. 1137–1216). Cambridge: Cambridge University Press.Google Scholar
- Clarke, L. B. (2006). Worst cases: Terror and catastrophe in the popular imagination. Chicago: University of Chicago Press.Google Scholar
- Egan, A., & Weatherson, B. (2009). Epistemic modality. Oxford: Oxford University Press.Google Scholar
- Ellis, J., Giudice, G., Mangano, M., Tkachev, I., & Wiedemann, U. (2008). Review of the safety of LHC collisions. http://www.cern.ch/lsag/LSAG-Report.pdf. Accessed 10 Nov 2012.
- European Commission. (2011). Commission staff working paper. Impact assessment. accompanying the document communication from the commission to the council, the European Parliament, the European Economic and Social Committee and the Committee of the Regions. Energy Roadmap 2050. COM(2011)885. http://ec.europa.eu/smart-regulation/impact/ia_carried_out/docs/ia_2011/sec_2011_1565_en.pdf. Accessed 12 Aug 2015.
- Gilboa, I., Postlewaite, A., & Schmeidler, D. (2009). Is it always rational to satisfy Savage’s axioms? Economics and Philosophy, 25(Special Issue 03): 285–296.Google Scholar
- Hartmut, G., Kokott, J., Kulessa, M., Luther, J., Nuscheler, F., Sauerborn, R., Schellnhuber, H-J., Schubert, R., & Schulze, E-D. (2003). World in transition: Towards sustainable energy systems. German Advisory Council on Global Change Flagship Report. http://www.wbgu.de/fileadmin/templates/dateien/veroeffentlichungen/hauptgutachten/jg2003/wbgu_jg2003_engl.pdf. Accessed 12 Aug 2015.
- Hansen, J., Sato, M., Russell, G., & Kharecha, P. (2013). Climate sensitivity, sea level and atmospheric carbon dioxide. Philosophical Transactions of the Royal Society A-Mathematical Physical and Engineering Sciences, 371 (20120294).Google Scholar
- Heal, G., & Millner, A. (2013). Uncertainty and decision in climate change economics. NBER working paper No. 18929. http://www.nber.org/papers/w18929.pdf. Accessed 12 Aug 2015.
- Jeffrey, R. (1965). The logic of decision. Chicago: University of Chicago Press.Google Scholar
- Jenkins, G. J., Murphy, J. M., Sexton, D. M. H., Lowe, J. A., Jones, P., & Kilsby, C. G. (2009). UK climate projections: Briefing report. Exeter: Met Office Hadley Centre.Google Scholar
- Lempert, R. J., Popper, S. W., & Bankes, S. C. (2003b). Shaping the next one hundred years: New methods for quantitative, long-term policy analysis. Santa Monica: RAND.Google Scholar
- Luce, R. D., & Raiffa, H. (1957). Games and decisions: Introduction and critical survey. New York: Wiley.Google Scholar
- Nordhaus, W. D., & Boyer, J. (2000). Warming the world: Economic models of climate change. Cambridge, MA: MIT Press.Google Scholar
- Rawls, J. (1971). A theory of justice. Cambridge: Harvard University Press.Google Scholar
- Rescher, N. (1984). The limits of science. Pittsburgh series in philosophy and history of science. Berkeley: University of California Press.Google Scholar
- Rescher, N. (2009). Ignorance: On the wider implications of deficient knowledge. Pittsburgh: University of Pittsburgh Press.Google Scholar
- Resnik, M. D. (1987b). Choices: An introduction to decision theory. Minneapolis: University of Minnesota Press.Google Scholar
- Savage, L. J. (1954). The foundation of statistics. New York: Wiley.Google Scholar