Learning Under Ambiguity
Abstract
This paper considers learning when the distinction between risk and ambiguity matters. It first describes thought experiments, dynamic variants of those provided by Ellsberg, that highlight a sense in which the Bayesian learning model is extreme - it models agents who are implausibly ambitious about what they can learn in complicated environments. The paper then provides a generalization of the Bayesian model that accommodates the intuitive choices in the thought experiments. In particular, the model allows decision-makers’ confidence about the environment to change — along with beliefs — as they learn. A calibrated portfolio choice application shows how this property induces a trend towards more stock market participation and investment.Download Info
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Paper provided by University of Rochester - Center for Economic Research (RCER) in its series RCER Working Papers with number 527.Length: 35 pages
Date of creation: Apr 2006
Date of revision:
Handle: RePEc:roc:rocher:527
Contact details of provider:
Postal: University of Rochester, Center for Economic Research, Department of Economics, Harkness 231 Rochester, New York 14627 U.S.A.
Related research
Keywords: ambiguity; learning; noisy signals; ambiguous signals; quality information; portfolio choice; portfolio diversification; Ellsberg Paradox;Other versions of this item:
- Larry Epstein & Martin Schneider, 2002. "Learning Under Ambiguity," RCER Working Papers 497, University of Rochester - Center for Economic Research (RCER), revised Mar 2005.
- D81 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Criteria for Decision-Making under Risk and Uncertainty
- D83 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Search, Learning, and Information
- D9 - Microeconomics - - Intertemporal Choice and Growth
- G11 - Financial Economics - - General Financial Markets - - - Portfolio Choice; Investment Decisions
- G12 - Financial Economics - - General Financial Markets - - - Asset Pricing
This paper has been announced in the following NEP Reports:
- NEP-ALL-2006-04-22 (All new papers)
- NEP-CBA-2006-04-22 (Central Banking)
- NEP-EVO-2006-04-22 (Evolutionary Economics)
- NEP-EXP-2006-04-22 (Experimental Economics)
- NEP-FIN-2006-04-22 (Finance)
- NEP-FMK-2006-04-22 (Financial Markets)
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