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Why uncertainty matters: discounting under intertemporal risk aversion and ambiguity

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  • Christian Traeger

Abstract

Uncertainty has an almost negligible impact on project value in the standard economic model. I show that a comprehensive evaluation of uncertainty and uncertainty attitude changes this picture fundamentally. The illustration of this result relies on the discount rate, which is the crucial determinant in balancing immediate costs against future benefits, and the single most important determinant of optimal mitigation policies in the integrated assessment of climate change. First, the paper removes an implicit assumption of (intertemporal or intrinsic) risk neutrality from the standard economic model. Second, the paper introduces aversion to non-risk uncertainty (ambiguity). I show a close formal similarity between the model of intertemporal risk aversion, which is a reformulation of the widespread Epstein–Zin–Weil model, and a recent model of smooth ambiguity aversion. I merge the models, achieving a threefold disentanglement between risk aversion, ambiguity aversion, and the propensity to smooth consumption over time. Copyright Springer-Verlag Berlin Heidelberg 2014

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  • Christian Traeger, 2014. "Why uncertainty matters: discounting under intertemporal risk aversion and ambiguity," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 56(3), pages 627-664, August.
  • Handle: RePEc:spr:joecth:v:56:y:2014:i:3:p:627-664
    DOI: 10.1007/s00199-014-0800-8
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    1. Luc Lauwers, 2016. "Intergenerational Equity, Efficiency, and Constructibility," Studies in Economic Theory, in: Graciela Chichilnisky & Armon Rezai (ed.), The Economics of the Global Environment, pages 191-206, Springer.
    2. Larry Karp & Jiangfeng Zhang, 2016. "Taxes Versus Quantities for a Stock Pollutant with Endogenous Abatement Costs and Asymmetric Information," Studies in Economic Theory, in: Graciela Chichilnisky & Armon Rezai (ed.), The Economics of the Global Environment, pages 493-533, Springer.
    3. Gierlinger, Johannes & Gollier, Christian, 2008. "Socially Efficient Discounting under Ambiguity Aversion," IDEI Working Papers 561, Institut d'Économie Industrielle (IDEI), Toulouse.
    4. Peter Klibanoff & Massimo Marinacci & Sujoy Mukerji, 2005. "A Smooth Model of Decision Making under Ambiguity," Econometrica, Econometric Society, vol. 73(6), pages 1849-1892, November.
    5. Pindyck, Robert S., 2012. "Uncertain outcomes and climate change policy," Journal of Environmental Economics and Management, Elsevier, vol. 63(3), pages 289-303.
    6. Lars Peter Hansen & Thomas J Sargent, 2014. "Robust Control and Model Uncertainty," World Scientific Book Chapters, in: UNCERTAINTY WITHIN ECONOMIC MODELS, chapter 5, pages 145-154, World Scientific Publishing Co. Pte. Ltd..
    7. Geir B. Asheim & Tapan Mitra & Bertil Tungodden, 2016. "Sustainable Recursive Social Welfare Functions," Studies in Economic Theory, in: Graciela Chichilnisky & Armon Rezai (ed.), The Economics of the Global Environment, pages 165-190, Springer.
    8. William D. Nordhaus, 2012. "Economic Policy in the Face of Severe Tail Events," Journal of Public Economic Theory, Association for Public Economic Theory, vol. 14(2), pages 197-219, March.
    9. Epstein, Larry G & Zin, Stanley E, 1991. "Substitution, Risk Aversion, and the Temporal Behavior of Consumption and Asset Returns: An Empirical Analysis," Journal of Political Economy, University of Chicago Press, vol. 99(2), pages 263-286, April.
    10. Campbell, John Y, 1996. "Understanding Risk and Return," Journal of Political Economy, University of Chicago Press, vol. 104(2), pages 298-345, April.
    11. Robert S. Pindyck, 2011. "Modeling the Impact of Warming in Climate Change Economics," NBER Chapters, in: The Economics of Climate Change: Adaptations Past and Present, pages 47-71, National Bureau of Economic Research, Inc.
    12. Traeger, Christian P., 2011. "Discounting and confidence," CUDARE Working Papers 120418, University of California, Berkeley, Department of Agricultural and Resource Economics.
    13. Graciela Chichilnisky, 2012. "Economic theory and the global environment," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 49(2), pages 217-225, February.
    14. Karp, Larry, 2005. "Global warming and hyperbolic discounting," Journal of Public Economics, Elsevier, vol. 89(2-3), pages 261-282, February.
    15. Klibanoff, Peter & Marinacci, Massimo & Mukerji, Sujoy, 2009. "Recursive smooth ambiguity preferences," Journal of Economic Theory, Elsevier, vol. 144(3), pages 930-976, May.
    16. Hayne E. Leland, 1968. "Saving and Uncertainty: The Precautionary Demand for Saving," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 82(3), pages 465-473.
    17. Philippe Weil, 1990. "Nonexpected Utility in Macroeconomics," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 105(1), pages 29-42.
    18. Larry G. Epstein & Stanley E. Zin, 2013. "Substitution, risk aversion and the temporal behavior of consumption and asset returns: A theoretical framework," World Scientific Book Chapters, in: Leonard C MacLean & William T Ziemba (ed.), HANDBOOK OF THE FUNDAMENTALS OF FINANCIAL DECISION MAKING Part I, chapter 12, pages 207-239, World Scientific Publishing Co. Pte. Ltd..
    19. Garth Heutel, 2012. "How Should Environmental Policy Respond to Business Cycles? Optimal Policy under Persistent Productivity Shocks," Review of Economic Dynamics, Elsevier for the Society for Economic Dynamics, vol. 15(2), pages 244-264, April.
    20. Stern,Nicholas, 2007. "The Economics of Climate Change," Cambridge Books, Cambridge University Press, number 9780521700801.
    21. Nengjiu Ju & Jianjun Miao, 2012. "Ambiguity, Learning, and Asset Returns," Econometrica, Econometric Society, vol. 80(2), pages 559-591, March.
    22. Charles Figuières & Mabel Tidball, 2016. "Sustainable Exploitation of a Natural Resource: A Satisfying Use of Chichilnisky’s Criterion," Studies in Economic Theory, in: Graciela Chichilnisky & Armon Rezai (ed.), The Economics of the Global Environment, pages 207-229, Springer.
    23. Kihlstrom, Richard E. & Mirman, Leonard J., 1974. "Risk aversion with many commodities," Journal of Economic Theory, Elsevier, vol. 8(3), pages 361-388, July.
    24. Hoel, Michael & Karp, Larry, 2002. "Taxes versus quotas for a stock pollutant," Resource and Energy Economics, Elsevier, vol. 24(4), pages 367-384, November.
    25. Gary D. Libecap & Richard H. Steckel, 2011. "The Economics of Climate Change: Adaptations Past and Present," NBER Books, National Bureau of Economic Research, Inc, number libe10-1.
    26. Michel Normandin & Pascal St-Amour, 1998. "Substitution, risk aversion, taste shocks and equity premia," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 13(3), pages 265-281.
    27. Plambeck, Erica L. & Hope, Chris & Anderson, John, 1997. "The model: Integrating the science and economics of global warming," Energy Economics, Elsevier, vol. 19(1), pages 77-101, March.
    28. repec:bla:jfinan:v:59:y:2004:i:4:p:1481-1509 is not listed on IDEAS
    29. William D. Nordhaus, 2009. "An Analysis of the Dismal Theorem," Cowles Foundation Discussion Papers 1686, Cowles Foundation for Research in Economics, Yale University.
    30. Martin L. Weitzman, 2011. "Additive Damages, Fat-Tailed Climate Dynamics, and Uncertain Discounting," NBER Chapters, in: The Economics of Climate Change: Adaptations Past and Present, pages 23-46, National Bureau of Economic Research, Inc.
    31. Hoel, Michael & Karp, Larry, 2001. "Taxes and quotas for a stock pollutant with multiplicative uncertainty," Journal of Public Economics, Elsevier, vol. 82(1), pages 91-114, October.
    32. Gollier, Christian, 2002. "Discounting an uncertain future," Journal of Public Economics, Elsevier, vol. 85(2), pages 149-166, August.
    33. Millner, Antony, 2013. "On welfare frameworks and catastrophic climate risks," Journal of Environmental Economics and Management, Elsevier, vol. 65(2), pages 310-325.
    34. Ravi Bansal & Dana Kiku & Amir Yaron, 2010. "Long Run Risks, the Macroeconomy, and Asset Prices," American Economic Review, American Economic Association, vol. 100(2), pages 542-546, May.
    35. Kelly, David L. & Kolstad, Charles D., 2001. "Malthus and Climate Change: Betting on a Stable Population," Journal of Environmental Economics and Management, Elsevier, vol. 41(2), pages 135-161, March.
    36. Weitzman, Martin L., 1998. "Why the Far-Distant Future Should Be Discounted at Its Lowest Possible Rate," Journal of Environmental Economics and Management, Elsevier, vol. 36(3), pages 201-208, November.
    37. Traeger, Christian P., 2010. "Subjective Risk, Confidence, and Ambiguity," CUDARE Working Papers 90461, University of California, Berkeley, Department of Agricultural and Resource Economics.
    38. Traeger, Christian P., 2010. "Intertemporal risk aversion – or – wouldn’t it be nice to tell whether Robinson Crusoe is risk averse?," CUDARE Working Paper Series 1102, University of California at Berkeley, Department of Agricultural and Resource Economics and Policy.
    39. Martin L. Weitzman, 2009. "On Modeling and Interpreting the Economics of Catastrophic Climate Change," The Review of Economics and Statistics, MIT Press, vol. 91(1), pages 1-19, February.
    40. Geoffrey Heal, 2009. "Climate Economics: A Meta-Review and Some Suggestions for Future Research," Review of Environmental Economics and Policy, Association of Environmental and Resource Economists, vol. 3(1), pages 4-21, Winter.
    41. Melissa Dell & Benjamin F. Jones & Benjamin A. Olken, 2012. "Temperature Shocks and Economic Growth: Evidence from the Last Half Century," American Economic Journal: Macroeconomics, American Economic Association, vol. 4(3), pages 66-95, July.
    42. Maccheroni, Fabio & Marinacci, Massimo & Rustichini, Aldo, 2006. "Dynamic variational preferences," Journal of Economic Theory, Elsevier, vol. 128(1), pages 4-44, May.
    43. Newell, Richard G. & Pizer, William A., 2003. "Regulating stock externalities under uncertainty," Journal of Environmental Economics and Management, Elsevier, vol. 45(2, Supple), pages 416-432, March.
    44. Karp, Larry & Zhang, Jiangfeng, 2006. "Regulation with anticipated learning about environmental damages," Journal of Environmental Economics and Management, Elsevier, vol. 51(3), pages 259-279, May.
    45. Christian Traeger, 2012. "Once Upon a Time Preference - How Rationality and Risk Aversion Change the Rationale for Discounting," CESifo Working Paper Series 3793, CESifo.
    46. William D. Nordhaus, 2007. "A Review of the Stern Review on the Economics of Climate Change," Journal of Economic Literature, American Economic Association, vol. 45(3), pages 686-702, September.
    47. Armon Rezai & Duncan K. Foley & Lance Taylor, 2016. "Global Warming and Economic Externalities," Studies in Economic Theory, in: Graciela Chichilnisky & Armon Rezai (ed.), The Economics of the Global Environment, pages 447-470, Springer.
    48. Azfar, Omar, 1999. "Rationalizing hyperbolic discounting," Journal of Economic Behavior & Organization, Elsevier, vol. 38(2), pages 245-252, February.
    49. Gilboa, Itzhak & Schmeidler, David, 1989. "Maxmin expected utility with non-unique prior," Journal of Mathematical Economics, Elsevier, vol. 18(2), pages 141-153, April.
    50. Libecap, Gary D. & Steckel, Richard H. (ed.), 2011. "The Economics of Climate Change," National Bureau of Economic Research Books, University of Chicago Press, number 9780226479880, September.
    51. Narayana R. Kocherlakota, 1996. "The Equity Premium: It's Still a Puzzle," Journal of Economic Literature, American Economic Association, vol. 34(1), pages 42-71, March.
    52. Ghirardato, Paolo & Maccheroni, Fabio & Marinacci, Massimo, 2004. "Differentiating ambiguity and ambiguity attitude," Journal of Economic Theory, Elsevier, vol. 118(2), pages 133-173, October.
    53. Annette Vissing-Jørgensen & Orazio P. Attanasio, 2003. "Stock-Market Participation, Intertemporal Substitution, and Risk-Aversion," American Economic Review, American Economic Association, vol. 93(2), pages 383-391, May.
    54. Martin L. Weitzman, 2007. "A Review of the Stern Review on the Economics of Climate Change," Journal of Economic Literature, American Economic Association, vol. 45(3), pages 703-724, September.
    55. Nicholas Stern, 2008. "The Economics of Climate Change," American Economic Review, American Economic Association, vol. 98(2), pages 1-37, May.
    56. Traeger, Christian P., 2011. "Discounting and confidence," Department of Agricultural & Resource Economics, UC Berkeley, Working Paper Series qt61m836d1, Department of Agricultural & Resource Economics, UC Berkeley.
    57. Kreps, David M & Porteus, Evan L, 1978. "Temporal Resolution of Uncertainty and Dynamic Choice Theory," Econometrica, Econometric Society, vol. 46(1), pages 185-200, January.
    58. Melissa Dell & Benjamin F. Jones & Benjamin A. Olken, 2008. "Climate Change and Economic Growth: Evidence from the Last Half Century," NBER Working Papers 14132, National Bureau of Economic Research, Inc.
    59. Keller, Klaus & Bolker, Benjamin M. & Bradford, D.F.David F., 2004. "Uncertain climate thresholds and optimal economic growth," Journal of Environmental Economics and Management, Elsevier, vol. 48(1), pages 723-741, July.
    60. Kelly, David L., 2005. "Price and quantity regulation in general equilibrium," Journal of Economic Theory, Elsevier, vol. 125(1), pages 36-60, November.
    61. William D. Nordhaus, 2011. "Estimates of the Social Cost of Carbon: Background and Results from the RICE-2011 Model," NBER Working Papers 17540, National Bureau of Economic Research, Inc.
    62. Daniel Ellsberg, 1961. "Risk, Ambiguity, and the Savage Axioms," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 75(4), pages 643-669.
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    More about this item

    Keywords

    Climate change; Discounting; Risk aversion; Ambiguity; Cost-benefit analysis; Intertemporal substitutability; Uncertainty; D61; D81; D90; H43; Q00; Q54;
    All these keywords.

    JEL classification:

    • D61 - Microeconomics - - Welfare Economics - - - Allocative Efficiency; Cost-Benefit Analysis
    • D81 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Criteria for Decision-Making under Risk and Uncertainty
    • D90 - Microeconomics - - Micro-Based Behavioral Economics - - - General
    • H43 - Public Economics - - Publicly Provided Goods - - - Project Evaluation; Social Discount Rate
    • Q00 - Agricultural and Natural Resource Economics; Environmental and Ecological Economics - - General - - - General
    • Q54 - Agricultural and Natural Resource Economics; Environmental and Ecological Economics - - Environmental Economics - - - Climate; Natural Disasters and their Management; Global Warming

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