Lecture Notes in Economics and Mathematical Systems 639 FoundingEditors: M.Beckmann H.P.Künzi ManagingEditors: Prof.Dr.G.Fandel FachbereichWirtschaftswissenschaften FernuniversitätHagen Feithstr.140/AVZII,58084Hagen,Germany Prof.Dr.W.Trockel InstitutfürMathematischeWirtschaftsforschung(IMW) UniversitätBielefeld Universitätsstr.25,33615Bielefeld,Germany EditorialBoard: H. Dawid, D. Dimitrow, A. Gerber, C-J. Haake, C. Hofmann, T. Pfeiffer, R. Slowi ń ski,W.H.M. Zijm Forfurthervolumes: http://www.springer.com/series/300 Boris Hirsch Monopsonistic Labour Markets and the Gender Pay Gap Theory and Empirical Evidence 123 Dr. Boris Hirsch Friedrich-Alexander-Universität Erlangen-Nürnberg Chair of Labour and Regional Economics Lange Gasse 20 90403 Nürnberg Germany [email protected] ISSN 0075-8442 ISBN 978-3-642-10408-4 e-ISBN978-3-642-10409-1 DOI10.1007/978-3-642-10409-1 Springer Heidelberg Dordrecht London New York LibraryofCongressControlNumber: 2010920969 © Springer-Verlag Berlin Heidelberg 2010 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, b roadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permissions for use must always be obtained from Springer. Violat- ions are liable for prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Cover design: SPi Publisher Services Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) To myparentsandgrandparents Acknowledgements I would like to thank all those people who have helped me in the course of my researchthatculminatedinthisPh.D.thesis. Firstandforemost,I am deeplyindebtedto myacademicsupervisors.My spe- cialthanksgotomyprincipalacademicsupervisorClausSchnabelforhisperpetual guidance and encouragement and for the many insightful discussions that helped greatly in forming this work. I am also deeply grateful to my second supervisor Jürgen Jerger for valuable advice and many useful suggestions that contributed substantiallytothisthesis’completion. Apartfrommysupervisors,I amparticularlygratefultomyco-authorsMarion König, Joachim Möller, Thorsten Schank, and Claus Schnabel. Large parts of Chapters6and9aregroundedonjointworkwiththem,andIbenefitedalotfrom theircommentsandsuggestions. Many thanks go to my colleagues at the Friedrich–Alexander–Universität Erlangen–Nürnbergand to the Bavarian Graduate Program in Economics and its members.Theprogram’sexcellentcoursesandseminarsprovedtobeinstrumental inwritingthisthesis.Theprogram’sgenerosityalsoallowedmetospendhalfayear at the Centre for EconomicPerformanceat the LondonSchoolof Economicsand Political Science, which has been a great stimulation in the course of writing this thesis.Iwouldliketothankforthecentre’swarmhospitalityandinparticularAlan Manningformanyfruitfulconversationsandhelpfulsuggestions. MyveryspecialthanksgotoJürgenDeinhard.Henotonlyproof-readthewhole thesis (includingthe technicalappendices)and pointedme at several inaccuracies and obscuritiesin the expositionbut also providedme with a lot of usefulecono- metriccommentsandsuggestions.Lastbutnotleast,Iowemydeepestgratitudeto myparentsandgrandparents,towhomIdedicatethiswork. vii Contents 1 Introduction................................................................... 1 1.1 WageSettingvs.WageTaking........................................ 1 1.2 ‘Classic’vs.‘New’Monopsony ...................................... 3 1.3 PlanoftheBook....................................................... 6 PartI SpatialMonopsony 2 SimpleStaticMonopsony.................................................... 11 3 Short-RunSpatialMonopsony.............................................. 15 3.1 TheBasicAssumptions ............................................... 15 3.2 TheElasticityoftheFirm’sAggregateLabourSupply.............. 19 3.3 ConvexityandElasticityofIndividualLabourSupply .............. 21 3.3.1 ConvexityRelativetoanExponential........................ 21 3.3.2 SpatialImplicationsofIndividualLabour Supply’sConvexity............................................ 27 3.4 Spatialvs.SpacelessMonopsony..................................... 28 3.5 Firms’InteractionandConjecturalVariations ....................... 31 3.6 TheShort-RunEquilibrium........................................... 35 3.7 Short-RunComparativeStatics ....................................... 38 3.8 Conclusions............................................................ 46 4 Long-RunSpatialMonopsony .............................................. 49 4.1 TheZero-ProfitLocus................................................. 50 4.2 TheWage-SettingCurve .............................................. 52 4.3 TheLong-RunEquilibrium ........................................... 55 4.4 Long-RunComparativeStatics ....................................... 60 4.4.1 Changesin thePositionoftheZero-Profit LocusandtheWage-SettingCurve........................... 61 4.4.2 ComparativeStatics in the Fixed Costs andtheWorkerDensity....................................... 62 4.4.3 ComparativeStaticsintheMarginalRevenue ProductofLabour............................................. 65 4.4.4 ComparativeStaticsintheTravelCost....................... 67 ix x Contents 4.5 Long-Run Spatial Monopsony under Linear IndividualLabourSupply............................................. 70 4.5.1 TheLöschianEquilibrium.................................... 75 4.5.2 TheGreenhut–OhtaEquilibrium ............................. 78 4.5.3 TheHotelling–SmithiesEquilibrium......................... 79 4.6 Long-Run Spatial Monopsony with Constant IndividualLabourSupply............................................. 82 4.6.1 The Hotelling–Smithies and the Greenhut–OhtaEquilibrium .................................. 83 4.6.2 AllowingforVaryingParticipation........................... 87 4.6.3 TheLöschianEquilibrium.................................... 90 4.7 Conclusions............................................................ 92 5 SpatialMonopsonyandtheGenderPayGap............................. 95 5.1 TheGenderPayGapandBeckerianvs.Robinsonian Discrimination......................................................... 95 5.2 TheModel.............................................................. 98 5.2.1 TheBasicAssumptions....................................... 98 5.2.2 Firm-LevelLabour Supply and Firms’ Wage-SettingBehaviour ......................................100 5.2.3 TheEquilibriumandItsProperties...........................103 5.3 Conclusions............................................................108 6 SpatialMonopsony and RegionalDifferencesin the GenderPayGap..............................................................113 6.1 TheoreticalConsiderations............................................114 6.2 EmpiricalSpecification................................................116 6.3 Data.....................................................................119 6.4 DescriptiveEvidence..................................................123 6.5 MultivariateEvidence.................................................125 6.6 Conclusions............................................................128 PartII DynamicMonopsony 7 SimpleDynamicMonopsony................................................133 8 AGeneralEquilibriumModelofDynamicMonopsony .................137 8.1 SomeIntroductoryRemarks ..........................................137 8.2 TheModel..............................................................139 8.2.1 TheBasicAssumptions.......................................139 8.2.2 Workers’ReservationWage ..................................141 8.2.3 Firms’Steady-StateLabourSupply..........................143 8.2.4 TheSteady-StateEquilibriumandItsProperties ............144 8.3 SomeConcludingRemarks ...........................................148 Contents xi 9 DynamicMonopsonyandtheGenderPayGap...........................151 9.1 ASimpleMeasureofOn-the-JobSearchFrictions..................153 9.2 A Semi-StructuralEstimation Approachto the Firm-LevelLabourSupplyElasticity.................................155 9.2.1 CombiningSimple DynamicMonopsony andtheBurdett–MortensenModel...........................155 9.2.2 IntroducingStochasticJob-to-JobTransitions...............157 9.2.3 Introducing Elastic Transitions fromandtoNon-Employment................................158 9.2.4 Procedurefor Identifyingthe Long-Run LabourSupplyElasticityattheLeveloftheFirm...........160 9.2.5 EmpiricalSpecification .......................................160 9.2.6 RelatedEmpiricalLiterature..................................163 9.3 Data.....................................................................164 9.4 GenderDifferencesinSearchFrictions ..............................168 9.5 EstimatesoftheGenderDifferencein Long-Run Firm-LevelLabourSupplyElasticities...............................173 9.5.1 TransitiontoEmployment ....................................174 9.5.2 TransitiontoNon-Employment...............................181 9.5.3 HiringfromEmployment.....................................187 9.5.4 EstimatesoftheLong-RunFirm-LevelLabour SupplyElasticities.............................................192 9.6 Conclusions............................................................199 10 ConcludingRemarks.........................................................201 A Appendix:SpatialMonopsony..............................................207 A.1 ProofofRemark3.2...................................................207 A.2 ProofofExample3.5..................................................208 A.3 ProofofProposition3.3...............................................210 A.4 ProofofProposition3.5...............................................217 A.5 TheSlopeoftheZero-ProfitLocusintheLöschian Long-RunEquilibrium ................................................220 A.6 ProofofLemma4.1 ...................................................220 A.7 ProofofLemma4.3 ...................................................222 A.8 ComparativeStaticsunderLinearSpatialMonopsony ..............226 A.9 TheImplicitSolutionfortheLong-RunHotelling– Smithies Equilibrium Wage in the Linear Model...................................................................227 A.10 ProofofCorollary5.3.................................................228 A.11 AppendixtoChapter6 ................................................229 B Appendix:DynamicMonopsony............................................231 B.1 TheRelationbetweentheFirm’sShort-andLong-Run LabourSupplyElasticity..............................................231 xii Contents B.2 Workers’OptimalReservationWage.................................232 B.3 ProofofProposition8.1:Workers’ExpectedWage .................233 B.4 ProofofEquation(9.1)................................................233 B.5 ProofofEquation(9.12)...............................................235 B.6 ProofofEquation(9.17)...............................................236 B.7 AppendixtoChapter9 ................................................236 References...........................................................................245 Index.................................................................................257