Thu, 07 Aug 2008 21:34:23 BST CiteULike: Tag uncertainty http://www.citeulike.org/tag/uncertainty CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/zhenbo_cheng/article/465989 <i>Science, Vol. 310, No. 5754. (9 December 2005), pp. 1680-1683.</i><br /><br />Much is known about how people make decisions under varying levels of probability (risk). Less is known about the neural basis of decision-making when probabilities are uncertain because of missing information (ambiguity). In decision theory, ambiguity about probabilities should not affect choices. Using functional brain imaging, we show that the level of ambiguity in choices correlates positively with activation in the amygdala and orbitofrontal cortex, and negatively with a striatal system. Moreover, striatal activity correlates positively with expected reward. Neurological subjects with orbitofrontal lesions were insensitive to the level of ambiguity and risk in behavioral choices. These data suggest a general neural circuit responding to degrees of uncertainty, contrary to decision theory. Neural Systems Responding to Degrees of Uncertainty in Human Decision-Making Ming Hsu Meghana Bhatt Ralph Adolphs Daniel Tranel Colin Camerer doi:10.1126/science.1115327 Science, Vol. 310, No. 5754. (9 December 2005), pp. 1680-1683. 2006-01-16T11:14:30-00:00 2005 Science 310 5754 1680 1683 decisionmaking reward uncertainty http://www.citeulike.org/user/xjlai/article/505089 <i>Natural Hazards, Vol. 37, No. 3. (March 2006), pp. 263-276.</i> Towards Formulation of a Space-borne System for Early Warning of Floods: Can Cost-Effectiveness Outweigh Prediction Uncertainty? Faisal Hossain doi:10.1007/s11069-005-4645-0 Natural Hazards, Vol. 37, No. 3. (March 2006), pp. 263-276. 2006-02-14T12:46:10-00:00 2006 Natural Hazards 0921-030X 37 3 263 276 Springer flood rs uncertainty http://www.citeulike.org/user/wnpx/article/1551114 <i>Advances in Information Systems (2004), pp. 4-13.</i><br /><br />In this paper we informally and formally defined what we mean by uncertain- ignorant information in relational databases and data warehouses. We classify proposed extensions to the relational data model that can represent and retrieve incomplete information. There are many different kinds of temporal ignorant information including information that is fuzzy, imprecise, indeterminate, indefinite, missing, partial, possible, probabilistic, unknown, uncertain, or vague. We will explore each variety of temporal ignorant information in detail with reference to database and data-warehouse design. On Uncertainty and Data-Warehouse Design Panagiotis Chountas Ilias Petrounias Christos Vasilakis Andy Tseng Elia El-Darzi Krassimir Atanassov Vassilis Kodogiannis Advances in Information Systems (2004), pp. 4-13. 2007-08-10T08:53:38-00:00 2004 Advances in Information Systems 4 13 database dataintegration uncertainty http://www.citeulike.org/user/wandall/article/1168621 <i>(01 August 1997)</i><br /><br />The proliferation of chemical substances in commerce poses scientific and philosophical problems. The scientific challenge is to develop data, methodologies, and techniques for identifying and assessing toxic substances before they cause harm to human beings and the environment. The philosophical problem is how much scientific information we should demand for this task consistent with other social goals we might have. In this book, Cranor utilizes material from ethics, philosophy of law, epidemiology, tort law, regulatory law, and risk assessment, to argue that the scientific evidential standards used in tort law and administrative law to control toxics ought to be evaluated with the purposes of the law in mind. Demanding too much for this purpose will slow the evaluation and lead to an excess of toxic substances left unidentified and unassessed, thus leaving the public at risk. Demanding too little may impose other costs. An appropriate balance between these social concerns must be found. Justice requires we use evidentiary standards more appropriate to the legal institutions in question and resist the temptation to demand the most intensive scientific evaluation of each substance subject to legal action. Regulating Toxic Substances: A Philosophy of Science and the Law (Environmental Ethics and Science Policy Series) Carl Cranor (01 August 1997) 2007-03-17T13:16:44-00:00 1997 Oxford University Press animal_studies causality epistemology ethics evidence justification regulation risk_assessment risk_management uncertainty http://www.citeulike.org/user/wandall/article/707405 <i>Risk Analysis, Vol. 26, No. 3. (June 2006), pp. 583-584.</i> Epidemiologic Data and Standards: Response to Kundi L Kheifets J Sahl R Shimkhada M Repacholi doi:10.1111/j.1539-6924.2006.00779.x Risk Analysis, Vol. 26, No. 3. (June 2006), pp. 583-584. 2006-06-22T14:56:53-00:00 2006 Risk Analysis 0272-4332 26 3 583 584 Blackwell Publishing epidemiology policy precaution risk_assessment uncertainty http://www.citeulike.org/user/wandall/article/707406 <i>Risk Analysis, Vol. 26, No. 3. (June 2006), pp. 579-581.</i> Comment on Developing Policy in the Face of Scientific Uncertainty: Interpreting 0.3 T or 0.4 T Cutpoints from EMF Epidemiologic Studies by Kheifets et al. in Risk Analysis, 25(4), 927935 Michael Kundi doi:10.1111/j.1539-6924.2006.00778.x Risk Analysis, Vol. 26, No. 3. (June 2006), pp. 579-581. 2006-06-22T14:56:53-00:00 2006 Risk Analysis 0272-4332 26 3 579 581 Blackwell Publishing epidemiology policy risk_management uncertainty http://www.citeulike.org/user/wandall/article/1697166 <i>Futures, Vol. 39, No. 9. (November 2007), pp. 1117-1130.</i><br /><br />A central subcategory of futures research is technology foresight. There is a concern that today's technology foresight processes do not serve technology-political decision-making and strategy processes of companies well enough. The regional level needs to be emphasized, too, and the inclusion of a wide variety of actors and organizations. There is a danger that results of foresight processes are not absorbed into regional strategy-making processes, leading to a "black hole of interpretation and implementation of foresight knowledge". Particularly knowledge, but also data and information are crucial concepts in foresight processes. An important issue is how to transform foresight information into future-oriented innovation knowledge. Concrete tools and institutional settings to enhance data, information and knowledge quality in foresight processes and strategy work are needed. This article investigates limitations of established foresight processes and planning approaches, limitations in practical utilization of results of foresight processes, and quality of data, information and knowledge as concrete tools and as a systematic response to limitations. The article is partly based on empirical results from a technology foresight survey undertaken in Finland in 2005. The research responds to societal and academic interest by combining the fields of (i) futures research and (ii) data, information and knowledge quality. Future-oriented considerations are not routine tasks, which makes it especially challenging and important to ensure that these processes benefit from data, information and knowledge of good quality. Quality of data, information and knowledge in regional foresight processes Tuomo Uotila Helina Melkas doi:10.1016/j.futures.2007.03.019 Futures, Vol. 39, No. 9. (November 2007), pp. 1117-1130. 2007-09-26T12:42:02-00:00 2007 Futures 39 9 1117 1130 data uncertainty http://www.citeulike.org/user/wandall/article/1151399 <i>PLoS Medicine, Vol. 2, No. 8. (1 August 2005), e124.</i><br /><br />Summary There is increasing concern that most current published research findings are false. The probability that a research claim is true may depend on study power and bias, the number of other studies on the same question, and, importantly, the ratio of true to no relationships among the relationships probed in each scientific field. In this framework, a research finding is less likely to be true when the studies conducted in a field are smaller; when effect sizes are smaller; when there is a greater number and lesser preselection of tested relationships; where there is greater flexibility in designs, definitions, outcomes, and analytical modes; when there is greater financial and other interest and prejudice; and when more teams are involved in a scientific field in chase of statistical significance. Simulations show that for most study designs and settings, it is more likely for a research claim to be false than true. Moreover, for many current scientific fields, claimed research findings may often be simply accurate measures of the prevailing bias. In this essay, I discuss the implications of these problems for the conduct and interpretation of research. Why Most Published Research Findings Are False John Ioannidis doi:10.1371/journal.pmed.0020124 PLoS Medicine, Vol. 2, No. 8. (1 August 2005), e124. 2007-03-09T15:04:00-00:00 2005 PLoS Medicine 2 8 e124 conflict_of_interest expert_judgment false_positive judgement registry replication statistics uncertainty http://www.citeulike.org/user/wandall/article/988650 <i>Br J Psychiatry, Vol. 178, No. 1. (1 January 2001), pp. 84-85.</i><br /><br />10.1192/bjp.178.1.84 Violence risk prediction in practice G Szmukler Br J Psychiatry, Vol. 178, No. 1. (1 January 2001), pp. 84-85. 2006-12-11T14:31:29-00:00 2001 Br J Psychiatry 178 1 84 85 false_positivefalse_negative risk_assessment uncertainty value http://www.citeulike.org/user/wandall/article/1061919 <i>Journal of General Internal Medicine</i> Reactions to Uncertainty and the Accuracy of Diagnostic Mammography Patricia Carney Joyce Yi Linn Abraham Diana Miglioretti Erin Aiello Martha Gerrity Lisa Reisch Eric Berns Edward Sickles Joann Elmore doi:10.1007/s11606-006-0036-9 Journal of General Internal Medicine 2007-01-23T12:08:50-00:00 Journal of General Internal Medicine histopathology judgement mammography uncertainty http://www.citeulike.org/user/wandall/article/1152758 <i>Med Hypotheses, Vol. 53, No. 3. (September 1999), pp. 253-259.</i><br /><br />When faced with medical decisions involving uncertain outcomes, the principles of decision theory hold that we should select the option with the highest expected utility to maximize health over time. Whether a decision proves right or wrong can be learned only in retrospect, when it may become apparent that another course of action would have been preferable. This realization may bring a sense of loss, or regret. When anticipated regret is compelling, a decision maker may choose to violate expected utility theory to avoid regret. We formulate a concept of acceptable regret in medical decision making that explicitly introduces the patient's attitude toward loss of health due to a mistaken decision into decision making. In most cases, minimizing expected regret results in the same decision as maximizing expected utility. However, when acceptable regret is taken into consideration, the threshold probability below which we can comfortably withhold treatment is a function only of the net benefit of the treatment, and the threshold probability above which we can comfortably administer the treatment depends only on the magnitude of the risks associated with the therapy. By considering acceptable regret, we develop new conceptual relations that can help decide whether treatment should be withheld or administered, especially when the diagnosis is uncertain. This may be particularly beneficial in deciding what constitutes futile medical care. Acceptable regret in medical decision making. B Djulbegovic I Hozo A Schwartz KM McMasters doi:10.1054/mehy.1998.0020 Med Hypotheses, Vol. 53, No. 3. (September 1999), pp. 253-259. 2007-03-10T11:07:32-00:00 1999 Med Hypotheses 0306-9877 53 3 253 259 expert_judgment false_positive judgement uncertainty http://www.citeulike.org/user/wandall/article/115039 <i>(01 October 2003)</i><br /><br />Uncertainty is a fundamental and unavoidable feature of daily life; in order to deal with uncertaintly intelligently, we need to be able to represent it and reason about it. In this book, Joseph Halpern examines formal ways of representing uncertainty and considers various logics for reasoning about it. While the ideas presented are formalized in terms of definitions and theorems, the emphasis is on the philosophy of representing and reasoning about uncertainty; the material is accessible and relevant to researchers and students in many fields, including computer science, artificial intelligence, economics (particularly game theory), mathematics, philosophy, and statistics.<br /> <br /> Halpern begins by surveying possible formal systems for representing uncertainty, including probability measures, possibility measures, and plausibility measures. He considers the updating of beliefs based on changing information and the relation to Bayes' theorem; this leads to a discussion of qualitative, quantitative, and plausibilistic Bayesian networks. He considers not only the uncertainty of a single agent but also uncertainty in a multi-agent framework. Halpern then considers the formal logical systems for reasoning about uncertainty. He discusses knowledge and belief; default reasoning and the semantics of default; reasoning about counterfactuals, and combining probability and counterfactuals; belief revision; first-order modal logic; and statistics and beliefs. He includes a series of exercises at the end of each chapter. Reasoning about Uncertainty Joseph Halpern (01 October 2003) 2005-03-05T20:11:59-00:00 2003 The MIT Press probability uncertainty http://www.citeulike.org/user/wandall/article/1269889 <i>Sci Am, Vol. 292, No. 6. (June 2005), pp. 96-101.</i> Doubt is their product. D Michaels Sci Am, Vol. 292, No. 6. (June 2005), pp. 96-101. 2007-05-01T08:50:38-00:00 2005 Sci Am 0036-8733 292 6 96 101 doubt industry uncertainty http://www.citeulike.org/user/wandall/article/937816 <i>Foundations of Chemistry, Vol. V6, No. 1. (1 January 2004), pp. 49-63.</i> Prediction, Explanation, and Dioxin Biochemistry: Science in Public Policy Heather Douglas doi:10.1023/B:FOCH.0000020995.75920.81 Foundations of Chemistry, Vol. V6, No. 1. (1 January 2004), pp. 49-63. 2006-11-09T13:42:33-00:00 2004 Foundations of Chemistry V6 1 49 63 dioxine epa explanation false_positivefalse_negative judgement mechanism philosophy policy prediction ra_guidelines risk risk_assessment toxicology uncertainty http://www.citeulike.org/user/wandall/article/1238408 <i>Futures, Vol. 39, No. 6. (August 2007), pp. 669-684.</i><br /><br />How do professional futurists contend with prognostic uncertainty? There is an impressive body of medical-sociological research on how medical staff deals with uncertainty. We have used these insights to study patterns and manners in foresight practice that might not be evident otherwise. The question "Do professional futurists use approaches to deal with uncertainty that resemble those of medical staff?" is addressed by ongoing ethnographic research in Dutch foresight practice. The observed manners are grouped into four analytic categories: the construction of solidity, numeric discourse, communication habits and experience as anchor. In this paper, the construction of solidity and experience as anchor are described in detail. It is further more suggested that "certainification" is a possible upshot of these manners in use. Dealing with prognostic uncertainty Marjolein van Asselt Jessica Mesman Van`t Futures, Vol. 39, No. 6. (August 2007), pp. 669-684. 2007-04-20T09:00:14-00:00 2007 Futures 39 6 669 684 foresight future uncertainty http://www.citeulike.org/user/walp/article/2562253 <i>pp. 338-345.</i><br /><br />ions, Decisions, and Uncertainty, Providence, RI, USA, July 1997 Incremental Tradeoff Resolution in Qualitative Probabilistic Networks Chao-Lin Liu and Michael P. Wellman University of Michigan AI Laboratory Ann Arbor, MI 48109-2110 fchaolin, wellmang@umich.edu Abstract Qualitative probabilistic reasoning in a Bayesian network often reveals tradeoffs: relationships that are ambiguous due to competing qualitative influences. We present two techniques that combine qualitative and numeric... Incremental Tradeoff Resolution in Qualitative Probabilistic Networks Chao Liu Michael Wellman pp. 338-345. 2008-03-19T15:23:29-00:00 338 345 probability qualitative representation uncertainty http://www.citeulike.org/user/walp/article/2562196 <i>(1994), pp. 171-179.</i><br /><br />In this essay I present a general characterization of qualitative probability, including a partial taxonomy of possible approaches. I discuss some of these in further depth, identify central issues, and suggest some general comparisons. 1. Introduction In the standard theory of probability, degrees of belief for events or propositions take values in the real interval [0,1]. From degrees of belief on the primitive propositions, the theory dictates degrees of belief for various compound and... Some Varieties of Qualitative Probability Michael Wellman (1994), pp. 171-179. 2008-03-19T15:22:53-00:00 1994 171 179 qualitative representation uncertainty http://www.citeulike.org/user/walp/article/2562150 <i>(1990), pp. 41-60.</i> Can Uncertainty Management be Realized in a Finite Totally Ordered Probability Algebra? Yang Xiang Michael Beddoes David Poole (1990), pp. 41-60. 2008-03-19T14:55:20-00:00 1990 41 60 North-Holland Publishing Co. qualitative representation uncertainty http://www.citeulike.org/user/voiklis/article/975615 <i>The American Journal of Sociology, Vol. 100, No. 2. (1994), pp. 313-345.</i><br /><br />An experiment is used to investigate the effects of uncertainty on pattern of exchange. The role of reputation as an important factor related to the formation of stable exchange relations is examined. In addition, some of the consequences of differences patterns of exchange-in particular, how different exchange conditions lead to different levels of trust among trading partners-are investigated. The results of the experiment indicate significant differences in the level of commitment, concern for one's own and others' reputation, and the level of trust that emerge when uncertainty (in the form of information asymmetries) is varied. The Emergence of Exchange Structures: An Experimental Study of Uncertainty, Commitment, and Trust Peter Kollock The American Journal of Sociology, Vol. 100, No. 2. (1994), pp. 313-345. 2006-12-05T18:58:39-00:00 1994 The American Journal of Sociology 100 2 313 345 social-capital trust uncertainty http://www.citeulike.org/user/vlachmore/article/1727994 <i>(2000), pp. 999-1006.</i><br /><br />Support vector machines have met with signi cant success in numerous real-world learning tasks. However, like most machine learning algorithms, they are generally applied using a randomly selected training set classified in advance. In many settings, we also have the option of using pool-based active learning. Instead of using a randomly selected training set, the learner has access to a pool of unlabeled instances and can request the labels for some number of them. We introduce a new algorithm ... Support Vector Machine Active Learning with Applications to Text Classification Simon Tong Daphne Koller (2000), pp. 999-1006. 2007-10-04T17:17:59-00:00 2000 999 1006 Morgan Kaufmann Publishers, San Francisco, US active active_learning based classification learning machines sampling support text uncertainty vector http://www.citeulike.org/user/vlachmore/article/1727968 <i>(2000), pp. 111-118.</i> Query Learning with Large Margin Classifiers Colin Campbell Nello Cristianini Alex Smola (2000), pp. 111-118. 2007-10-04T17:05:59-00:00 2000 111 118 Morgan Kaufmann Publishers Inc. active active_learning based learning machines sampling support uncertainty vector http://www.citeulike.org/user/vlachmore/article/716139 <i>J. Mach. Learn. Res., Vol. 2 (2002), pp. 45-66.</i> Support vector machine active learning with applications to text classification Simon Tong Daphne Koller doi:10.1023/A:1009715923555 J. Mach. Learn. Res., Vol. 2 (2002), pp. 45-66. 2006-06-29T19:38:54-00:00 2002 J. Mach. Learn. Res. 1533-7928 2 45 66 MIT Press active active_learning based classification learning machines sampling support text uncertainty vector http://www.citeulike.org/user/vlachmore/article/1727960 <i>(2000), pp. 839-846.</i> Less is More: Active Learning with Support Vector Machines Greg Schohn David Cohn (2000), pp. 839-846. 2007-10-04T17:02:49-00:00 2000 839 846 Morgan Kaufmann Publishers Inc. active active_learning based criterion learning machines sampling stopping support uncertainty vector http://www.citeulike.org/user/vlachmore/article/1727809 <i>(1994), pp. 3-12.</i> A sequential algorithm for training text classifiers David Lewis William Gale doi:10.1145/62437.62470 (1994), pp. 3-12. 2007-10-04T15:51:16-00:00 1994 3 12 Springer-Verlag New York, Inc. active active_learning based classification learning sampling text uncertainty http://www.citeulike.org/user/vlachmore/article/1727805 <i>Mach. Learn., Vol. 15, No. 2. (May 1994), pp. 201-221.</i> Improving Generalization with Active Learning David Cohn Les Atlas Richard Ladner doi:10.1023/A:1022673506211 Mach. Learn., Vol. 15, No. 2. (May 1994), pp. 201-221. 2007-10-04T15:49:19-00:00 1994 Mach. Learn. 0885-6125 15 2 201 221 Kluwer Academic Publishers active active_learning based learning sampling uncertainty http://www.citeulike.org/user/tschenk/article/841325 <i>Journal of Economic Behavior & Organization, Vol. 38, No. 2. (1 February 1999), pp. 155-178.</i><br /><br />We propose a model of consumption and saving based on Kahneman and Tversky's Prospect Theory that implies a fundamental asymmetry in consumption behavior inconsistent with other models of consumption. When there is sufficient income uncertainty, a person resists lowering consumption in response to bad news about future income. This resistance is greater than the resistance to increasing consumption in response to good news. We present empirical evidence from five countries that confirms this behavior. Loss aversion in a consumption-savings model David Bowman Deborah Minehart Matthew Rabin doi:10.1016/S0167-2681(99)00004-9 Journal of Economic Behavior & Organization, Vol. 38, No. 2. (1 February 1999), pp. 155-178. 2006-09-12T19:45:09-00:00 1999 Journal of Economic Behavior & Organization 38 2 155 178 consumptiontheory economics jinhua_zhao_seminar prospecttheory riskaversion uncertainty http://www.citeulike.org/user/tschenk/article/99680 <i>Econometrica, Vol. 47, No. 2. (1979), pp. 263-292.</i><br /><br />This paper presents a critique of expected utility theory as a descriptive model of decision making under risk, and develops an alternative model, called prospect theory. Choices among risky prospects exhibit several pervasive effects that are inconsistent with the basic tenets of utility theory. In particular, people underweight outcomes that are merely probable in comparison with outcomes that are obtained with certainty. This tendency, called the certainty effect, contributes to risk aversion in choices involving sure gains and to risk seeking in choices involving sure losses. In addition, people generally discard components that are shared by all prospects under consideration. This tendency, called the isolation effect, leads to inconsistent preferences when the same choice is presented in different forms. An alternative theory of choice is developed, in which value is assigned to gains and losses rather than to final assets and in which probabilities are replaced by decision weights. The value function is normally concave for gains, commonly convex for losses, and is generally steeper for losses than for gains. Decision weights are generally lower than the corresponding probabilities, except in the range of low probabilities. Overweighting of low probabilities may contribute to the attractiveness of both insurance and gambling. Prospect Theory: An Analysis of Decision under Risk Daniel Kahneman Amos Tversky Econometrica, Vol. 47, No. 2. (1979), pp. 263-292. 2005-02-20T19:58:05-00:00 1979 Econometrica 47 2 263 292 decisiontheory economics gametheory jinhua_zhao_seminar uncertainty utilitytheory http://www.citeulike.org/user/toomash/article/105955 <i>(10 September 1992)</i><br /><br />Recent intellectual advances in the theory of uncertainty and information are presented in this book, which unifies many important but partial results into a satisfying single picture, making it clear how the economics of uncertainty and information generalizes and extends standard economic analysis. Part 1 covers the economics of uncertainty: each person adapts to a given fixed state of knowledge by making an optimal choice among the immediate "terminal" actions available. These choices in turn determine the overall market equilibrium reflecting the social distribution of risk-bearing. In Part 2, covering the economics of information, the state of knowledge is no longer held fixed, and individuals can overcome their ignorance by "informational" actions. The text also addresses many specific topics such as insurance, the Capital Asset Pricing Model, auctions, deterrence of entry, and research and invention. The Analytics of Uncertainty and Information (Cambridge Surveys of Economic Literature) Jack Hirshleifer John Riley (10 September 1992) 2005-02-27T14:42:30-00:00 1992 Cambridge University Press economics uncertainty http://www.citeulike.org/user/toomash/article/1025524 <i>Econometrica, Vol. 64, No. 2. (1996), pp. 261-294.</i><br /><br />This paper uses the Panel Study of Income Dynamics to test whether risk-sharing is complete between or within American families. The tests accommodate a wide variety in the configuration and availability of family data. The test results reject inter- as well as intra-family full risk-sharing even assuming that leisure is endogenous or that leisure and consumption are nonseparable. Risk-Sharing between and within Families Fumio Hayashi Joseph Altonji Laurence Kotlikoff Econometrica, Vol. 64, No. 2. (1996), pp. 261-294. 2007-01-04T22:30:52-00:00 1996 Econometrica 64 2 261 294 411-2 uncertainty http://www.citeulike.org/user/toomash/article/1025523 <i>The Journal of Political Economy, Vol. 104, No. 6. (1996), pp. 1227-1262.</i><br /><br />We analyze how relative wage movements among birth cohorts and education groups affected the distribution of household consumption and economic welfare. Our empirical work draws on the best available cross-sectional data sets to construct synthetic panel data on U.S. consumption, labor supply, and wages during the 1980s. We find that low-frequency movements in the cohort-education structure of pretax hourly wages among men drove large changes in the distribution of household consumption. The results constitute a spectacular failure of between-group consumption insurance, a failure not explained by existing theories of informationally constrained optimal consumption behavior. A welfare analysis indicates that the cost of between-group consumption variability is larger than the cost of aggregate consumption variability by two orders of magnitude. Relative Wage Movements and the Distribution of Consumption Orazio Attanasio Steven Davis The Journal of Political Economy, Vol. 104, No. 6. (1996), pp. 1227-1262. 2007-01-04T22:30:52-00:00 1996 The Journal of Political Economy 104 6 1227 1262 411-2 uncertainty http://www.citeulike.org/user/toomash/article/1025522 <i>The Journal of Political Economy, Vol. 99, No. 5. (1991), pp. 957-976.</i><br /><br />Are consumers effectively insured against idiosyncratic shocks to income or wealth, either by formal institutions such as charities, private insurance, and government programs or by informal mechanisms such as gifts and "loans" from relatives, friends, and neighbors? Under full insurance, consumption growth should be cross-sectionally independent of idiosyncratic variables that are exogenous to consumers. This proposition is tested by cross-sectional regressions of consumption growth on a variety of exogenous variables. Full insurance is rejected for long illness and involuntary job loss, but not for spells of unemployment, loss of work due to strike, and an involuntary move. A Simple Test of Consumption Insurance John Cochrane The Journal of Political Economy, Vol. 99, No. 5. (1991), pp. 957-976. 2007-01-04T22:30:51-00:00 1991 The Journal of Political Economy 99 5 957 976 411-2 uncertainty http://www.citeulike.org/user/toomash/article/1025521 <i>The Journal of Political Economy, Vol. 99, No. 5. (1991), pp. 928-956.</i><br /><br />This paper tests implications of full consumption insurance. The object is to determine how much mileage can be obtained from a model with complete markets, with such features as private information or liquidity constraints omitted. The implication exploited is that individual consumption responds to aggregate risk but not to idiosyncratic risk. The test involves regressing the change in household consumption onto the change in aggregate consumption and other right-hand-side variables such as the change in household income and change in employment status. All variables other than the change in aggregate consumption are predicted to be insignificant in explaining the change in household consumption. With observations on consumption and income for 10,695 households from the Consumer Expenditure Survey, the results are mixed. The results for one specification (exponential utility) are mostly consistent with full consumption insurance; the results for the other specification (power utility) are not. Full Insurance in the Presence of Aggregate Uncertainty Barbara Mace The Journal of Political Economy, Vol. 99, No. 5. (1991), pp. 928-956. 2007-01-04T22:30:49-00:00 1991 The Journal of Political Economy 99 5 928 956 411-2 uncertainty http://www.citeulike.org/user/toomash/article/850394 <i>(01 September 2004)</i><br /><br />This book updates and advances the theory of expected utility as applied to risk analysis and financial decision making. Von Neumann and Morgenstern pioneered the use of expected utility theory in the 1940s, but most utility functions used in financial management are still relatively simplistic and assume a mean-variance world. Taking into account recent advances in the economics of risk and uncertainty, this book focuses on richer applications of expected utility in finance, macroeconomics, and environmental economics.<br /> <br /> The book covers these topics: expected utility theory and related concepts; the standard portfolio problem of choice under uncertainty involving two different assets; P the basic hyperplane separation theorem and log-supermodular functions as technical tools for solving various decision-making problems under uncertainty; s choice involving multiple risks; the Arrow-Debreu portfolio problem; consumption and saving; the equilibrium price of risk and time in an Arrow-Debreu economy; and dynamic models of decision making when a flow of information on future risks is expected over time. The book is appropriate for both students and professionals. Concepts are presented intuitively as well as formally, and the theory is balanced by empirical considerations. Each chapter concludes with a problem set. The Economics of Risk and Time Christian Gollier (01 September 2004) 2006-09-20T01:58:21-00:00 2004 The MIT Press 410-1 books risk uncertainty http://www.citeulike.org/user/toomash/article/115367 <i>The American Economic Review, Vol. 91, No. 2. (2001), pp. 60-66.</i> Robust Control and Model Uncertainty Lars Hansen Thomas Sargent doi:10.2307/2677734 The American Economic Review, Vol. 91, No. 2. (2001), pp. 60-66. 2005-03-06T17:05:04-00:00 2001 The American Economic Review 91 2 60 66 economics robust_control uncertainty http://www.citeulike.org/user/tomisc/article/2932256 <i>Futures, Vol. 39, No. 8. (October 2007), pp. 920-929.</i><br /><br />The progress of human thought in recent centuries has brought not only new knowledge but also new (and sometimes disturbing) questions that tug at the foundations of knowledge itself. The opening years of the twentieth century were marked by optimistic expectations of ever-increasing certainty and scientific and technological progress. Yet the century turned out to be an age of growing cracks in the facade of classical certainty, as relativity, quantum physics and chaos theory each deepened our understanding of the universe yet raised fundamental challenges to ideas about knowledge. Today, although reductionist and mechanistic ways of thinking still prevail in much contemporary thinking about economics, global security and environmental problems, we can nevertheless contemplate an "end of objectivity" in which we realize that we do not stand outside of the systems we study. From certainty to uncertainty: Thought, theory and action in a postmodern world David Peat doi:10.1016/j.futures.2007.03.007 Futures, Vol. 39, No. 8. (October 2007), pp. 920-929. 2008-06-26T22:56:20-00:00 2007 Futures 39 8 920 929 knowledge philsci postmodern reductionism uncertainty http://www.citeulike.org/user/tim-fewtrell/article/1397518 <i>Hydrological Processes, Vol. 21, No. 14. (2007), pp. 1979-1980.</i><br /><br />No Abstract. Just say NO to equifinality Stuart Hamilton doi:10.1002/hyp.6800 Hydrological Processes, Vol. 21, No. 14. (2007), pp. 1979-1980. 2007-06-18T19:37:59-00:00 2007 Hydrological Processes 21 14 1979 1980 equifinality modelling uncertainty http://www.citeulike.org/user/tim-fewtrell/article/1464470 <i>Water Resources Research, Vol. 34, No. 4., pp. 751-764.</i> Toward improved calibration of hydrologic models: Multiple and noncommensurable measures of information Hoshin Gupta Soroosh Sorooshian Patrice Yapo Water Resources Research, Vol. 34, No. 4., pp. 751-764. 2007-07-18T08:54:05-00:00 Water Resources Research 34 4 751 764 calibration hydrological identifiability uncertainty http://www.citeulike.org/user/tim-fewtrell/article/1464436 <i>Hydrological Processes, Vol. 14, No. 14. (2000), pp. 2605-2606.</i><br /><br />No Abstract On model uncertainty, risk and decision making Keith Beven doi:10.1002/1099-1085(20001015)14:14<2605::AID-HYP400>3.0.CO;2-W Hydrological Processes, Vol. 14, No. 14. (2000), pp. 2605-2606. 2007-07-18T08:39:35-00:00 2000 Hydrological Processes 14 14 2605 2606 calibration uncertainty http://www.citeulike.org/user/tim-fewtrell/article/2744821 <i>Water Resources Research, Vol. 42 (18 March 2006), W03S04.</i> Getting the right answers for the right reasons: Linking measurements, analyses, and models to advance the science of hydrology James Kirchner doi:10.1029/2005WR004362 Water Resources Research, Vol. 42 (18 March 2006), W03S04. 2008-05-02T09:34:37-00:00 2006 Water Resources Research 42 W03S04 equifinality identifiability uncertainty http://www.citeulike.org/user/stkhu/article/117535 <i>(1977)</i><br /><br />A broadly applicable algorithm for computing maximum likelihood estimates from incomplete data is presented at various levels of generality. Theory showing the monotone behaviour of the likelihood and convergence of the algorithm is derived. Many examples are sketched, including missing value situations, applications to grouped, censored or truncated data, finite mixture models, variance component estimation, hyperparameter estimation, iteratively reweighted least squares and factor analysis. Maximum Likelihood from Incomplete Data via the EM Algorithm AP Dempster NM Laird DB Rubin doi:10.2307/2984875 (1977) 2005-03-08T19:21:34-00:00 1977 uncertainty http://www.citeulike.org/user/stkhu/article/1366351 <i>Water Resources Management, Vol. 21, No. 5. (May 2007), pp. 835-847.</i> Optimal Groundwater Remediation Under Uncertainty Using Multi-objective Optimization Mantoglou Aristotelis Kourakos George doi:10.1007/s11269-006-9109-0 Water Resources Management, Vol. 21, No. 5. (May 2007), pp. 835-847. 2007-06-05T21:37:04-00:00 2007 Water Resources Management 0920-4741 21 5 835 847 Springer genetic-algorithm hydroinformatics optimization options-generation uncertainty uncertainty-hydrology http://www.citeulike.org/user/sternshein/article/1560305 <i>Nat Neurosci (5 August 2007)</i><br /><br />Our decisions are guided by outcomes that are associated with decisions made in the past. However, the amount of influence each past outcome has on our next decision remains unclear. To ensure optimal decision-making, the weight given to decision outcomes should reflect their salience in predicting future outcomes, and this salience should be modulated by the volatility of the reward environment. We show that human subjects assess volatility in an optimal manner and adjust decision-making accordingly. This optimal estimate of volatility is reflected in the fMRI signal in the anterior cingulate cortex (ACC) when each trial outcome is observed. When a new piece of information is witnessed, activity levels reflect its salience for predicting future outcomes. Furthermore, variations in this ACC signal across the population predict variations in subject learning rates. Our results provide a formal account of how we weigh our different experiences in guiding our future actions. Learning the value of information in an uncertain world. Timothy E J Behrens Mark W Woolrich Mark E Walton Matthew F S Rushworth doi:10.1038/nn1954 Nat Neurosci (5 August 2007) 2007-08-14T13:37:12-00:00 2007 Nat Neurosci 1097-6256 brian jessica kristina learning nichola uncertainty http://www.citeulike.org/user/sternshein/article/1060523 <i>Mem Cognit, Vol. 34, No. 6. (September 2006), pp. 1368-1375.</i><br /><br />The notion of a link between time and memory is intuitively appealing and forms the core assumption of temporal distinctiveness models. Distinctiveness models predict that items that are temporally isolated from their neighbors at presentation should be recalled better than items that are temporally crowded. By contrast, event-based theories consider time to be incidental to the processes that govern memory, and such theories would not imply a temporal isolation advantage unless participants engaged in a consolidation process (e.g., rehearsal or selective encoding) that exploited the temporal structure of the list. In this report, we examine two studies that assessed the effect of temporal distinctiveness on memory, using auditory (Experiment 1) and auditory and visual (Experiment 2) presentation with unpredictably varying interitem intervals. The results show that with unpredictable intervals temporal isolation does not benefit memory, regardless of presentation modality. Distinctiveness revisited: unpredictable temporal isolation does not benefit short-term serial recall of heard or seen events. LM Nimmo S Lewandowsky Mem Cognit, Vol. 34, No. 6. (September 2006), pp. 1368-1375. 2007-01-22T18:30:35-00:00 2006 Mem Cognit 0090-502X 34 6 1368 1375 auditory memory patterns uncertainty visual http://www.citeulike.org/user/sternshein/article/482141 <i>Nature Neuroscience, Vol. 9, No. 2. (22 January 2006), pp. 276-282.</i> Activity in prefrontal cortex during dynamic selection of action sequences Bruno Averbeck Jeong-Woo Sohn Daeyeol Lee doi:10.1038/nn1634 Nature Neuroscience, Vol. 9, No. 2. (22 January 2006), pp. 276-282. 2006-01-27T00:56:57-00:00 2006 Nature Neuroscience 1097-6256 9 2 276 282 Nature Publishing Group prefrontal sequence_learning uncertainty http://www.citeulike.org/user/stefanherzog/article/205455 <i>J Neurosci, Vol. 25, No. 13. (30 March 2005), pp. 3304-3311.</i><br /><br />Many decisions are made under uncertainty; that is, with limited information about their potential consequences. Previous neuroimaging studies of decision making have implicated regions of the medial frontal lobe in processes related to the resolution of uncertainty. However, a different set of regions in dorsal prefrontal and posterior parietal cortices has been reported to be critical for selection of actions to unexpected or unpredicted stimuli within a sequence. In the current study, we induced uncertainty using a novel task that required subjects to base their decisions on a binary sequence of eight stimuli so that uncertainty changed dynamically over time (from 20 to 50%), depending on which stimuli were presented. Activation within prefrontal, parietal, and insular cortices increased with increasing uncertainty. In contrast, within medial frontal regions, as well as motor and visual cortices, activation did not increase with increasing uncertainty. We conclude that the brain response to uncertainty depends on the demands of the experimental task. When uncertainty depends on learned associations between stimuli and responses, as in previous studies, it modulates activation in the medial frontal lobes. However, when uncertainty develops over short time scales as information is accumulated toward a decision, dorsal prefrontal and posterior parietal contributions are critical for its resolution. The distinction between neural mechanisms subserving different forms of uncertainty resolution provides an important constraint for neuroeconomic models of decision making. Decisions under uncertainty: probabilistic context influences activation of prefrontal and parietal cortices. SA Huettel AW Song G McCarthy doi:10.1523/JNEUROSCI.5070-04.2005 J Neurosci, Vol. 25, No. 13. (30 March 2005), pp. 3304-3311. 2005-05-19T20:12:31-00:00 2005 J Neurosci 1529-2401 25 13 3304 3311 ambiguity fmri neuroeconomics uncertainty http://www.citeulike.org/user/stefanherzog/article/210426 <i>J Neurosci, Vol. 25, No. 19. (11 May 2005), pp. 4806-4812.</i><br /><br />Anticipated reward magnitude and probability comprise dual components of expected value (EV), a cornerstone of economic and psychological theory. However, the neural mechanisms that compute EV have not been characterized. Using event-related functional magnetic resonance imaging, we examined neural activation as subjects anticipated monetary gains and losses that varied in magnitude and probability. Group analyses indicated that, although the subcortical nucleus accumbens (NAcc) activated proportional to anticipated gain magnitude, the cortical mesial prefrontal cortex (MPFC) additionally activated according to anticipated gain probability. Individual difference analyses indicated that, although NAcc activation correlated with self-reported positive arousal, MPFC activation correlated with probability estimates. These findings suggest that mesolimbic brain regions support the computation of EV in an ascending and distributed manner: whereas subcortical regions represent an affective component, cortical regions also represent a probabilistic component, and, furthermore, may integrate the two. Distributed neural representation of expected value. B Knutson J Taylor M Kaufman R Peterson G Glover doi:10.1523/JNEUROSCI.0642-05.2005 J Neurosci, Vol. 25, No. 19. (11 May 2005), pp. 4806-4812. 2005-05-25T14:27:33-00:00 2005 J Neurosci 1529-2401 25 19 4806 4812 fmri probablity reward uncertainty value http://www.citeulike.org/user/stefanherzog/article/206014 <i>Neuroimage, Vol. 21, No. 3. (March 2004), pp. 848-857.</i><br /><br />Behavioral evidence suggests that the perceived reason of uncertainty causes different coping strategies to be implemented, particularly frequency ratings with externally attributed uncertainty and memory search with internally attributed uncertainty. We used functional magnetic resonance imaging (fMRI) to investigate whether processes related to these different attributions of uncertainty differ also in their neural substrates. Participants had to predict events that were uncertain due to internal factors, that is, insufficient knowledge. Data were compared with a preceding study in which event prediction was uncertain due to external factors, that is, event probabilities. Parametric analyses revealed the posterior frontomedian cortex, that is, mesial Brodmann Area 8 (BA 8) as the common cortical substrate mediating processes related to uncertainty no matter what the cause of uncertainty. However, processes related to the two differently attributed types of uncertainty differed significantly in relation to the brain network that was coactivated. Only processes related to internally attributed uncertainty elicited activation within the mid-dorsolateral and posterior parietal areas known to underlie working memory (WM) functions. Together, findings from both experiments suggest that there is a common cerebral correlate for uncertain predictions but different correlates for coping strategies of uncertainty. Concluding, BA 8 reflects that we are uncertain, coactivated networks what we do to resolve uncertainty. Why am I unsure? Internal and external attributions of uncertainty dissociated by fMRI. KG Volz RI Schubotz DY von Cramon doi:10.1016/j.neuroimage.2003.10.028 Neuroimage, Vol. 21, No. 3. (March 2004), pp. 848-857. 2005-05-20T14:56:48-00:00 2004 Neuroimage 1053-8119 21 3 848 857 decision-making fmri neuroeconomics uncertainty http://www.citeulike.org/user/stefanherzog/article/206015 <i>Neuroimage, Vol. 19, No. 2 Pt 1. (June 2003), pp. 271-280.</i><br /><br />Many everyday life predictions rely on the experience and memory of event frequencies, i.e., natural samplings. We used functional magnetic resonance imaging (fMRI) to investigate the neural substrates of prediction under varying uncertainty based on a natural sampling approach. The study focused particularly on a comparison with other types of externally attributed uncertainty, such as guessing, and on the frontomedian cortex, which is known to be engaged in many types of decisions under uncertainty. On the basis of preceding stimulus cues, participants predicted events that occurred with probabilities ranging from p = 0.6 to p = 1.0. In contrast to certain predictions in a control task, predictions under uncertainty elicited activations within a posterior frontomedian area (mesial BA 8) and within a set of subcortical areas which are known to subserve dopaminergic modulations. The parametric analysis revealed that activation within the mesial BA 8 significantly increased with increasing uncertainty. A comparison with other types of uncertainty indicates that frontomedian correlates of frequency-based prediction appear to be comparable with those induced in long-term stimulus-response adaptation processes such as hypothesis testing, in contrast to those engaged in short-term error processing such as guessing. Predicting events of varying probability: uncertainty investigated by fMRI. KG Volz RI Schubotz DY von Cramon Neuroimage, Vol. 19, No. 2 Pt 1. (June 2003), pp. 271-280. 2005-05-20T14:59:58-00:00 2003 Neuroimage 1053-8119 19 2 Pt 1 271 280 decision-making fmri neuroeconomics uncertainty http://www.citeulike.org/user/stefanherzog/article/528200 <i>Organizational Behavior and Human Decision Processes, Vol. 99, No. 2. (March 2006), pp. 161-174.</i><br /><br />Previous research has shown that gamblers prefer numbers they choose themselves because this choice allows them to feel more in control of the (random) outcome. We identify other conditions under which people find numbers "special" (i.e., worthy of betting more on than other numbers). By manipulating gambling task type and assigning participants a number by an endogenous system outside their own control (as is done in numerology, astrology, and other paranormal systems), we find that indeed people prefer to bet on numbers derived from particular special systems. The mechanism underlying this preference is enjoyment with the task--not control. Further, the enjoyment associated with this "specialness" is related to the prevalence of certain types of numbers (i.e., numbers based on dates and names) in the fortune-telling world and not to other factors such as individuality or even belief in the associated system. We replicate these findings using actual money and show that this prevalence-to-enjoyment link already exists in memory for dates and names and is activated and strengthened by priming the fortune-telling systems relevant to those special random numbers. Finally, we present a model of special random numbers that integrates our findings with other determinants of valuation such as regret and subjective probability. Our results expand the realm of special random numbers beyond control. Our enjoyment model has implications not only for understanding gambling, but also for understanding how reasoning under uncertainty is influenced by little-understood phenomena (such as fortune-telling systems) without affecting subjective probability or actual beliefs. Special random numbers: Beyond the illusion of control Joseph Goodman Julie Irwin doi:10.1016/j.obhdp.2005.08.004 Organizational Behavior and Human Decision Processes, Vol. 99, No. 2. (March 2006), pp. 161-174. 2006-03-03T12:55:17-00:00 2006 Organizational Behavior and Human Decision Processes 99 2 161 174 decision-making enjoyment random randomness uncertainty http://www.citeulike.org/user/stefanherzog/article/315921 <i>Cereb Cortex (20 July 2005)</i><br /><br />Brain processing of reward information is essential for complex functions such as learning and motivation. Recent primate electrophysiological studies using concepts from information, economic and learning theories indicate that the midbrain may code two statistical parameters of reward information: a transient reward error prediction signal that varies linearly with reward probability and a sustained signal that varies highly non-linearly with reward probability and that is highest with maximal reward uncertainty (reward probability = 0.5). Here, using event-related functional magnetic resonance imaging, we disentangled these two signals in humans using a novel paradigm that systematically varied monetary reward probability, magnitude and expected reward value. The midbrain was activated both transiently with the error prediction signal and in a sustained fashion with reward uncertainty. Moreover, distinct activity dynamics were observed in post-synaptic midbrain projection sites: the prefrontal cortex responded to the transient error prediction signal while the ventral striatum covaried with the sustained reward uncertainty signal. These data suggest that the prefrontal cortex may generate the reward prediction while the ventral striatum may be involved in motivational processes that are useful when an organism needs to obtain more information about its environment. Our results indicate that distinct functional brain networks code different aspects of the statistical properties of reward information in humans. Neural Coding of Distinct Statistical Properties of Reward Information in Humans. Jean-Claude Dreher Philip Kohn Karen Faith Berman Cereb Cortex (20 July 2005) 2005-09-12T15:00:31-00:00 2005 Cereb Cortex 1047-3211 neuroeconomics neuroscience reward uncertainty