Piecewise additivity for non-expected utility
Author
Suggested Citation
DOI: 10.1007/s00199-015-0871-1
Download full text from publisher
As the access to this document is restricted, you may want to look for a different version below or search for a different version of it.
Other versions of this item:
- Craig S. Webb, 2015. "Piecewise Additivity for Nonexpected Utility," Economics Discussion Paper Series 1503, Economics, The University of Manchester.
References listed on IDEAS
- Alain Chateauneuf & Fabio Maccheroni & Massimo Marinacci & Jean-Marc Tallon, 2005.
"Monotone continuous multiple priors,"
Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 26(4), pages 973-982, November.
- Massimo Marinacci & Fabio Maccheroni & Alain Chateauneuf & Jean-Marc Tallon, 2003. "Monotone Continuous Multiple Priors," ICER Working Papers - Applied Mathematics Series 30-2003, ICER - International Centre for Economic Research.
- Alain Chateauneuf & Fabio Macheronni & Massimo Marinacci & Jean-Marc Tallon, 2005. "Monotone continuous multiple priors," Post-Print halshs-00177057, HAL.
- Alain Chateauneuf & Fabio Macheronni & Massimo Marinacci & Jean-Marc Tallon, 2005. "Monotone continuous multiple priors," Université Paris1 Panthéon-Sorbonne (Post-Print and Working Papers) halshs-00177057, HAL.
- Essid, Samir, 1997. "Choice under risk with certainty and potential effects: A general axiomatic model," Mathematical Social Sciences, Elsevier, vol. 34(3), pages 223-247, October.
- Itzhak Gilboa, 1988. "A Combination of Expected Utility and Maxmin Decision Criteria," Post-Print hal-00753244, HAL.
- Wakker, Peter P, 2001. "Testing and Characterizing Properties of Nonadditive Measures through Violations of the Sure-Thing Principle," Econometrica, Econometric Society, vol. 69(4), pages 1039-1059, July.
- Ludwig, Alexander & Zimper, Alexander, 2014.
"Biased Bayesian learning with an application to the risk-free rate puzzle,"
Journal of Economic Dynamics and Control, Elsevier, vol. 39(C), pages 79-97.
- Alexander Ludwig & Alexander Zimper, 2013. "Biased Bayesian learning with an application to the risk-free rate puzzle," Working Papers 201366, University of Pretoria, Department of Economics.
- Alexander Ludwig & Alexander Zimper, 2013. "Biased Bayesian Learning with an Application to the Risk-Free Rate Puzzle," Working Papers 390, Economic Research Southern Africa.
- Wakker,Peter P., 2010.
"Prospect Theory,"
Cambridge Books,
Cambridge University Press, number 9780521765015, October.
- Wakker,Peter P., 2010. "Prospect Theory," Cambridge Books, Cambridge University Press, number 9780521748681.
- Chateauneuf, Alain & Eichberger, Jurgen & Grant, Simon, 2007.
"Choice under uncertainty with the best and worst in mind: Neo-additive capacities,"
Journal of Economic Theory, Elsevier, vol. 137(1), pages 538-567, November.
- Grant, Simon & Chateauneuf, A. & Eichberger, J., 2002. "Choice under Uncertainty with the Best and Worst in Mind: Neo-additive Capacities," Working Papers 2002-10, Rice University, Department of Economics.
- Alain Chateauneuf & Jürgen Eichberger & Simon Grant, 2007. "Choice under uncertainty with the best and worst in mind: neo-additive capacities," Post-Print hal-00271279, HAL.
- Alain Chateauneuf & Jürgen Eichberger & Simon Grant, 2007. "Choice under uncertainty with the best and worst in mind: neo-additive capacities," Université Paris1 Panthéon-Sorbonne (Post-Print and Working Papers) hal-00271279, HAL.
- Chateauneuf, Alain & Eichberger, Jürgen & Grant, Simon, 2003. "Choice under Uncertainty with the Best and Worst in Mind: Neo-additive Capacities," Sonderforschungsbereich 504 Publications 03-10, Sonderforschungsbereich 504, Universität Mannheim;Sonderforschungsbereich 504, University of Mannheim.
- Chateauneuf, Alain & Eichberger, Jürgen & Grant, Simon, 2003. "Choice under uncertainty with the best and worst in mind : neo-additive capacities," Papers 03-10, Sonderforschungsbreich 504.
- Johannes W. Fedderke & Yang Liu, 2015.
"Accounting for Productivity Growth: Schumpeterian versus Semi-Endogenous Explanantions,"
Working Papers
554, Economic Research Southern Africa.
- Johannes W. Fedderke & Yang Liu, 2015. "Accounting for Productivity Growth: Schumpeterian versus Semi-Endogenous Explanations," Working Papers 47, Economic Research Southern Africa.
- Johannes Fedderke & Yang Liu, 2016. "Accounting for Productivity Growth Schumpeterian versus SemiEndogenous Explanations," Working Papers 7276, South African Reserve Bank.
- Eichberger, Jürgen & Grant, Simon & Lefort, Jean-Philippe, 2008.
"Neo-additive capacities and updating,"
Papers
08-31, Sonderforschungsbreich 504.
- Eichberger, Jürgen & Grant, Simon & Lefort, Jean-Philippe, 2008. "Neo-additive capacities and updating," Sonderforschungsbereich 504 Publications 08-31, Sonderforschungsbereich 504, Universität Mannheim;Sonderforschungsbereich 504, University of Mannheim.
- Eichberger, Jürgen & Grant, Simon & Lefort, Jean-Philippe, 2009. "Neo-additive capacities and updating," Working Papers 0490, University of Heidelberg, Department of Economics.
- Kopylov, Igor, 2007. "Subjective probabilities on "small" domains," Journal of Economic Theory, Elsevier, vol. 133(1), pages 236-265, March.
- Jürgen Eichberger & David Kelsey, 2014.
"Optimism And Pessimism In Games,"
International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 55(2), pages 483-505, May.
- Jurgen Eichberger & David Kelsey, 2006. "Optimism and Pessimism in Games," Discussion Papers 0605, University of Exeter, Department of Economics.
- Jurgen Eichberger & David Kelsey, 2009. "Optimism and Pessimism in Games," Discussion Papers 0905, University of Exeter, Department of Economics.
- repec:dau:papers:123456789/7604 is not listed on IDEAS
- Dominiak, Adam & Eichberger, Jürgen & Lefort, Jean-Philippe, 2012. "Agreeable trade with optimism and pessimism," Mathematical Social Sciences, Elsevier, vol. 64(2), pages 119-126.
- Jürgen Eichberger & Simon Grant & Jean-Philippe Lefort, 2012.
"Generalized neo-additive capacities and updating,"
International Journal of Economic Theory, The International Society for Economic Theory, vol. 8(3), pages 237-257, September.
- Jürgen Eichberger & Simon Grant & Jean-Philippe Lefort, 2012. "Generalized neo-additive capacities and updating," Post-Print hal-01615858, HAL.
- Mohammed Abdellaoui & Aurelien Baillon & Laetitia Placido & Peter P. Wakker, 2011.
"The Rich Domain of Uncertainty: Source Functions and Their Experimental Implementation,"
American Economic Review, American Economic Association, vol. 101(2), pages 695-723, April.
- Mohammed Abdellaoui & Laetitia Placido & Aurélien Baillon & P.P. Wakker, 2011. "The Rich Domain of Uncertainty: Source Functions and Their Experimental Implementation," Université Paris1 Panthéon-Sorbonne (Post-Print and Working Papers) hal-00609214, HAL.
- Mohammed Abdellaoui & Laetitia Placido & Aurélien Baillon & P.P. Wakker, 2011. "The Rich Domain of Uncertainty: Source Functions and Their Experimental Implementation," Post-Print hal-00609214, HAL.
- Jürgen Eichberger & David Kelsey, 2014.
"Optimism And Pessimism In Games,"
International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 55, pages 483-505, May.
- Jurgen Eichberger & David Kelsey, 2006. "Optimism and Pessimism in Games," Discussion Papers 0605, University of Exeter, Department of Economics.
- Jurgen Eichberger & David Kelsey, 2009. "Optimism and Pessimism in Games," Discussion Papers 0905, University of Exeter, Department of Economics.
- Gilboa, Itzhak, 1987.
"Expected utility with purely subjective non-additive probabilities,"
Journal of Mathematical Economics, Elsevier, vol. 16(1), pages 65-88, February.
- Gilboa, Itzhak, 1985. "Expected Utility with Purely Subjective Non-Additive Probabilities," Foerder Institute for Economic Research Working Papers 275389, Tel-Aviv University > Foerder Institute for Economic Research.
- Itzhak Gilboa, 1987. "Expected Utility with Purely Subjective Non-Additive Probabilities," Post-Print hal-00756291, HAL.
- Schmeidler, David, 1989.
"Subjective Probability and Expected Utility without Additivity,"
Econometrica, Econometric Society, vol. 57(3), pages 571-587, May.
- David Schmeidler, 1989. "Subjective Probability and Expected Utility without Additivity," Levine's Working Paper Archive 7662, David K. Levine.
- repec:cup:judgdm:v:9:y:2014:i:5:p:387-402 is not listed on IDEAS
- Craig R. Fox & Amos Tversky, 1995. "Ambiguity Aversion and Comparative Ignorance," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 110(3), pages 585-603.
- J L Ford & David Kelsey & W Pang, 2005. "Ambiguity in Financial Markets: Herding and Contrarian Behaviour," Discussion Papers 05-11, Department of Economics, University of Birmingham.
- Jürgen Eichberger & David Kelsey, 2011.
"Are the treasures of game theory ambiguous?,"
Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 48(2), pages 313-339, October.
- Eichberger, Jürgen & Kelsey, David, 2008. "Are the Treasures of Game Theory Ambiguous?," Sonderforschungsbereich 504 Publications 08-08, Sonderforschungsbereich 504, Universität Mannheim;Sonderforschungsbereich 504, University of Mannheim.
- Eichberger, Jürgen & Kelsey, David, 2008. "Are the Treasures of Game Theory Ambiguous?," Papers 08-08, Sonderforschungsbreich 504.
- repec:dau:papers:123456789/7332 is not listed on IDEAS
- Wakker, Peter P., 2005. "Decision-foundations for properties of nonadditive measures: general state spaces or general outcome spaces," Games and Economic Behavior, Elsevier, vol. 50(1), pages 107-125, January.
- Paolo Ghirardato & Fabio Maccheroni & Massimo Marinacci & Marciano Siniscalchi, 2003.
"A Subjective Spin on Roulette Wheels,"
Econometrica, Econometric Society, vol. 71(6), pages 1897-1908, November.
- Paolo Ghirardato & Fabio Maccheroni & Massimo Marinacci & Marciano Siniscalchi, 2001. "A subjective spin on roulette wheels," ICER Working Papers - Applied Mathematics Series 17-2001, ICER - International Centre for Economic Research, revised Aug 2001.
- Ghirardato, Paolo & Maccheroni, Fabio & Marinacci, Massimo & Siniscalchi, Marciano, 2001. "A Subjective Spin on Roulette Wheels," Working Papers 1127, California Institute of Technology, Division of the Humanities and Social Sciences.
- Jean-Philippe Lefort & Adam Dominiak, 2013. "Agreement theorem for neo-additive beliefs," Post-Print hal-01615841, HAL.
- Chow, Clare Chua & Sarin, Rakesh K, 2001. "Comparative Ignorance and the Ellsberg Paradox," Journal of Risk and Uncertainty, Springer, vol. 22(2), pages 129-139, March.
- J. Ford & D. Kelsey & W. Pang, 2013. "Information and ambiguity: herd and contrarian behaviour in financial markets," Theory and Decision, Springer, vol. 75(1), pages 1-15, July.
- Chew, Soo Hong & Sagi, Jacob S., 2008. "Small worlds: Modeling attitudes toward sources of uncertainty," Journal of Economic Theory, Elsevier, vol. 139(1), pages 1-24, March.
- Zimper, Alexander, 2012. "Asset pricing in a Lucas fruit-tree economy with the best and worst in mind," Journal of Economic Dynamics and Control, Elsevier, vol. 36(4), pages 610-628.
- Wakker, Peter, 1989. "Continuous subjective expected utility with non-additive probabilities," Journal of Mathematical Economics, Elsevier, vol. 18(1), pages 1-27, February.
- Wakker, Peter, 1996. "The sure-thing principle and the comonotonic sure-thing principle: An axiomatic analysis," Journal of Mathematical Economics, Elsevier, vol. 25(2), pages 213-227.
- Heath, Chip & Tversky, Amos, 1991. "Preference and Belief: Ambiguity and Competence in Choice under Uncertainty," Journal of Risk and Uncertainty, Springer, vol. 4(1), pages 5-28, January.
- Adam Dominiak & Jürgen Eichberger & Jean-Philippe Lefort, 2012. "Agreeable trade with pessimism and optimism," Post-Print hal-01615843, HAL.
- Mohammed Abdellaoui & Peter Wakker, 2005. "The Likelihood Method for Decision under Uncertainty," Theory and Decision, Springer, vol. 58(1), pages 3-76, February.
- Mohammed Abdellaoui & Olivier L’Haridon & Horst Zank, 2010.
"Separating curvature and elevation: A parametric probability weighting function,"
Journal of Risk and Uncertainty, Springer, vol. 41(1), pages 39-65, August.
- Olivier L'Haridon & Mohammed Abdellaoui & Horst Zank, 2010. "Separating curvature and elevation: A parametric probability weighting function," Post-Print hal-00528381, HAL.
- Machina, Mark J & Schmeidler, David, 1992. "A More Robust Definition of Subjective Probability," Econometrica, Econometric Society, vol. 60(4), pages 745-780, July.
- Webb, Craig S. & Zank, Horst, 2011.
"Accounting for optimism and pessimism in expected utility,"
Journal of Mathematical Economics, Elsevier, vol. 47(6), pages 706-717.
- Craig Webb & Horst Zank, 2011. "Accounting for Optimism and Pessimism in Expected Utility," Economics Discussion Paper Series 1111, Economics, The University of Manchester.
- Hong, Chew Soo & Wakker, Peter, 1996. "The Comonotonic Sure-Thing Principle," Journal of Risk and Uncertainty, Springer, vol. 12(1), pages 5-27, January.
- Wakker, Peter, 1993. "Clarification of some mathematical misunderstandings about Savage's foundations of statistics, 1954," Mathematical Social Sciences, Elsevier, vol. 25(2), pages 199-202, February.
- Joshua C. Teitelbaum, 2007. "A Unilateral Accident Model under Ambiguity," The Journal of Legal Studies, University of Chicago Press, vol. 36(2), pages 431-477, June.
- repec:dau:papers:123456789/8588 is not listed on IDEAS
- Adam Dominiak & Jean-Philippe Lefort, 2013. "Agreement theorem for neo-additive beliefs," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 52(1), pages 1-13, January.
- 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.
Citations
Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
Cited by:
- Craig S. Webb, 2017. "Piecewise linear rank-dependent utility," Theory and Decision, Springer, vol. 82(3), pages 403-414, March.
- Henderson, Vicky & Hobson, David & Tse, Alex S.L., 2017. "Randomized strategies and prospect theory in a dynamic context," Journal of Economic Theory, Elsevier, vol. 168(C), pages 287-300.
- Ulrich Schmidt & Horst Zank, 2022. "Chance theory: A separation of riskless and risky utility," Journal of Risk and Uncertainty, Springer, vol. 65(1), pages 1-32, August.
- Jinrui Pan & Craig S. Webb & Horst Zank, 2019. "Delayed probabilistic risk attitude: a parametric approach," Theory and Decision, Springer, vol. 87(2), pages 201-232, September.
- Katarzyna M. Werner & Horst Zank, 2019. "A revealed reference point for prospect theory," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 67(4), pages 731-773, June.
- Meng, Jingyi & Webb, Craig S. & Zank, Horst, 2024. "Mixture independence foundations for expected utility," Journal of Mathematical Economics, Elsevier, vol. 111(C).
Most related items
These are the items that most often cite the same works as this one and are cited by the same works as this one.- Craig S. Webb, 2017. "Piecewise linear rank-dependent utility," Theory and Decision, Springer, vol. 82(3), pages 403-414, March.
- Mohammed Abdellaoui & Horst Zank, 2023. "Source and rank-dependent utility," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 75(4), pages 949-981, May.
- Craig S. Webb, 2017. "Purely subjective variational preferences," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 64(1), pages 121-137, June.
- Katarzyna M. Werner & Horst Zank, 2019. "A revealed reference point for prospect theory," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 67(4), pages 731-773, June.
- Aurélien Baillon & Han Bleichrodt & Umut Keskin & Olivier L'Haridon & Author-Name: Chen Li, 2013. "Learning under ambiguity: An experiment using initial public offerings on a stock market," Economics Working Paper Archive (University of Rennes & University of Caen) 201331, Center for Research in Economics and Management (CREM), University of Rennes, University of Caen and CNRS.
- Alexander Ludwig & Alexander Zimper, 2013.
"A decision-theoretic model of asset-price underreaction and overreaction to dividend news,"
Annals of Finance, Springer, vol. 9(4), pages 625-665, November.
- Alexander Ludwig & Alexander Zimper, 2012. "A decision-theoretic model of asset-price underreaction and overreaction to dividend news," Working Papers 201223, University of Pretoria, Department of Economics.
- Alexander Ludwig & Alexander Zimper, 2012. "A decision-theoretic model of asset-price underreaction and overreaction to dividend news," Working Papers 296, Economic Research Southern Africa.
- Dominiak, Adam & Lee, Min Suk, 2017. "Coherent Dempster–Shafer equilibrium and ambiguous signals," Journal of Mathematical Economics, Elsevier, vol. 68(C), pages 42-54.
- Aurélien Baillon & Han Bleichrodt & Umut Keskin & Olivier l’Haridon & Chen Li, 2018.
"The Effect of Learning on Ambiguity Attitudes,"
Management Science, INFORMS, vol. 64(5), pages 2181-2198, May.
- Aurélien Baillon & Han Bleichrodt & Umut Keskin & Olivier L’haridon & Chen Li, 2018. "The Effect of Learning on Ambiguity Attitudes," Post-Print halshs-01525391, HAL.
- Dean, Mark & Ortoleva, Pietro, 2017.
"Allais, Ellsberg, and preferences for hedging,"
Theoretical Economics, Econometric Society, vol. 12(1), January.
- Mark Dean & Pietro Ortoleva, 2012. "Allais, Ellsberg, and Preferences for Hedging," Working Papers 2012-2, Brown University, Department of Economics.
- Izhakian, Yehuda, 2017. "Expected utility with uncertain probabilities theory," Journal of Mathematical Economics, Elsevier, vol. 69(C), pages 91-103.
- Emy Lécuyer & Jean-Philippe Lefort, 2021. "Put–call parity and generalized neo-additive pricing rules," Theory and Decision, Springer, vol. 90(3), pages 521-542, May.
- Nicolas Lampach & Sandrine Spaeter, 2016. "The Efficiency of (strict) Liability Rules revised in Risk and Ambiguity," Working Papers of BETA 2016-29, Bureau d'Economie Théorique et Appliquée, UDS, Strasbourg.
- Dominiak, Adam & Lefort, Jean-Philippe, 2015. "“Agreeing to disagree” type results under ambiguity," Journal of Mathematical Economics, Elsevier, vol. 61(C), pages 119-129.
- Groneck, Max & Ludwig, Alexander & Zimper, Alexander, 2016.
"A life-cycle model with ambiguous survival beliefs,"
Journal of Economic Theory, Elsevier, vol. 162(C), pages 137-180.
- Max Groneck & Ludwig, Alexander & Alexander Zimper, 2013. "A Life-Cycle Model with Ambiguous Survival Beliefs," MEA discussion paper series 201305, Munich Center for the Economics of Aging (MEA) at the Max Planck Institute for Social Law and Social Policy.
- Alexander Ludwig & Alexander Zimper & Max Groneck, 2014. "A Life-Cycle Model with Ambiguous Survival Beliefs," Working Papers 473, Economic Research Southern Africa.
- Max Groneck & Alexander Ludwig & Alexander Zimper, 2013. "A Life-Cycle Model with Ambiguous Survival Beliefs," Working Paper Series in Economics 63, University of Cologne, Department of Economics, revised 22 Nov 2013.
- Max Groneck & Alexander Ludwig, 2014. "A Life-Cycle Model with Ambiguous Survival Beliefs," Working Papers 201465, University of Pretoria, Department of Economics.
- Groneck, Max & Ludwig, Alexander & Zimper, Alexander, 2015. "A life-cycle model with ambiguous survival beliefs," SAFE Working Paper Series 73, Leibniz Institute for Financial Research SAFE, revised 2015.
- Yehuda Izhakian, 2012. "Ambiguity Measurement," Working Papers 12-01, New York University, Leonard N. Stern School of Business, Department of Economics.
- Mohammed Abdellaoui & Han Bleichrodt & Cédric Gutierrez, 2023. "Unpacking Overconfident Behavior When Betting on Oneself," Post-Print hal-04383402, HAL.
- Katarzyna Werner & Horst Zank, 2012. "Foundations for Prospect Theory Through Probability Midpoint Consistency," Economics Discussion Paper Series 1210, Economics, The University of Manchester.
- Zhihua Li & Julia Müller & Peter P. Wakker & Tong V. Wang, 2018.
"The Rich Domain of Ambiguity Explored,"
Management Science, INFORMS, vol. 64(7), pages 3227-3240, July.
- Müller, Julia & Li, Zhihua & Wakker, Peter P. & Wang, Tong V., 2016. "The Rich Domain of Ambiguity Explored," VfS Annual Conference 2016 (Augsburg): Demographic Change 145734, Verein für Socialpolitik / German Economic Association.
- Alexander Zimper, 2011.
"Do Bayesians Learn Their Way Out of Ambiguity?,"
Decision Analysis, INFORMS, vol. 8(4), pages 269-285, December.
- Alexander Zimper, 2011. "Do Bayesians learn their way out of ambiguity?," Working Papers 240, Economic Research Southern Africa.
- Gijs van de Kuilen & Peter P. Wakker, 2011.
"The Midweight Method to Measure Attitudes Toward Risk and Ambiguity,"
Management Science, INFORMS, vol. 57(3), pages 582-598, March.
- van de Kuilen, G. & Wakker, P.P., 2011. "The midweight method to measure attitudes towards risk and ambiguity," Other publications TiSEM c58a6884-24cc-4cab-ae2f-a, Tilburg University, School of Economics and Management.
More about this item
Keywords
Optimism; Pessimism; Inverse-S; Choquet expected utility; NEO-additive capacities; Probabilistic sophistication; D81;All these keywords.
JEL classification:
- D81 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Criteria for Decision-Making under Risk and Uncertainty
Statistics
Access and download statisticsCorrections
All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:spr:joecth:v:60:y:2015:i:2:p:371-392. See general information about how to correct material in RePEc.
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Sonal Shukla or Springer Nature Abstracting and Indexing (email available below). General contact details of provider: http://www.springer.com .
Please note that corrections may take a couple of weeks to filter through the various RePEc services.