An Economic Answer to Unsolicited Communication ABSTRACT

  • 格式:pdf
  • 大小:206.66 KB
  • 文档页数:11

AnEconomicAnswertoUnsolicitedCommunicationThedeLoderUniversityOfMichiganElectricalEngineeringandComputerSciencetloder@umich.eduMarshallVanAlstyneUniversityofMichiganSchoolofInformationmvanalst@umich.eduRickWashUniversityofMichiganCenterforInformationTechnologyIntegration

rwash@umich.edu

ABSTRACTWeexploreanalternativeapproachtospambasedoneco-nomicratherthantechnologicalorregulatoryscreeningmech-anisms.Weemployamodelofemailvaluewhichsup-portstwointuitivenotions:1)mechanismsdesignedtopro-motevaluablecommunicationcanoftenoutperformthosedesignedmerelytoblockwastefulcommunication,and2)designersofsuchmechanismsshouldshiftfocusawayfromtheinformationinthemessagetotheinformationknowntothesender.Wethenuseprinciplesofinformationasymme-trytocausepeoplewhoknowinglymisusecommunicationtoincurhighercoststhanthosewhodonot.Incertaincases,thoughnotall,wecanshowthisapproachleavesre-cipientsbetteroffthanevenanidealizedor“perfect”filterthatcostsnothingandmakesnomistakes.Ourmechanismalsoaccountsforindividualdifferencesinopportunitycosts,andallowsforbi-directionalwealthtransferswhilefacilitat-ingbothsendersignalingandrecipientscreening.1

CategoriesandSubjectDescriptorsK.4.4[ComputersandSociety]:ElectronicCommerce—DistributedcommercialTransactions,paymentschemes;K.4.2[ComputersandSociety]:SocialIssues—AbuseandCrimeinvolvingcomputers

GeneralTermsEconomics

Keywordsmechanismdesign,spam,UCE,screening,signaling,filter-ing,informationeconomics,informationasymmetry

1.INTRODUCTION1ThismaterialisbaseduponworksupportedbytheNa-

tionalScienceFoundationunderGrantNo.0114368.

Permissiontomakedigitalorhardcopiesofallorpartofthisworkforpersonalorclassroomuseisgrantedwithoutfeeprovidedthatcopiesarenotmadeordistributedforprofitorcommercialadvantageandthatcopiesbearthisnoticeandthefullcitationonthefirstpage.Tocopyotherwise,torepublish,topostonserversortoredistributetolists,requirespriorspecificpermissionand/orafee.EC’04,May17–20,2004,NewYork,NewYork,USA.Copyright2004ACM1-58113-711-0/04/0005...$5.00.

Duetoitslowcost,speed,andfreedomfromgeographi-calconstraints,emailhasbecomeaubiquitousandarguablyessentialmeansofcommunication.Unfortunately,thesamepropertiesthatmakeitsouseful,combinedwithitsopen-nessandtrustingdesign,enableunscrupulousmarketerstobroadcastemailtountargetedaudiences.Theresultisun-necessaryandunwarrantedcostsforrecipients.Recentestimatesindicatemorethan60%ofemailisnowspam,thevolumeofspamisgrowingrapidly,andworldwidecostsexceed$20billionannually[12].Theenormousquan-tityofunwantedcommunicationshasreducedthesignal-to-noiseratioofemailtosuchanextentthatithasbecomeanissueofnationalimportance.Legislativeandtechnologicalsolutionscontinuetobetheprimarymeanspursuedtostoporlimitspam.Nofewerthaneightbills2havebeenintroducedintoCongressoverthelastseveralyears,andPresidentBushsignedtheCAN-SPAMActintolawinDecember,2003.Morethanhalfthestates[18]haveenactedlawstoregulateemail.Concurrently,thetechnologyindustryismobilizingtoprovideproductsandservicesintendedtogivebacksomemeasureofcontroltomailboxowners.In2002,atleast$54.4millionwasinvestedinanti-spamstartups,up65%fromthepreviousyear[14].Usingprinciplesofinformationeconomics,wedevelopanalternativetothepopularmechanismsforfilteringandban-ningcommunicationsaswellastochallenge-responsesys-temswhichverifysenderidentity.Basedonaverysimplemodel,weshowthatuseoftherightmechanism-onethatfacilitatescommunicationratherthanblocksitorbansit-canimprovesocialwelfare.Ourmechanismencouragesselectivetargetingofmessages,hasdynamicallyadjustingprices(accountingforarecipi-ent’svalueoftime),dependsonexpostverification–notexanteclassification–ofcontentsothatdeceitfulsubjectlinesdonotmatter,transferswealthdirectlytorecipientsandsorequiresneitherrebatemechanismsnorgovernmentoversight,anditisincentivecompatible.Recipientshavereasontoadoptit,notonlytomanagetheirincomingmes-sages,buttoreceivewealthfromthosewhowouldaskfortheirattention.Last,themechanismisbi-directional,al-lowingbothsignalingandscreening.Theremainderofthispaperproceedsasfollows.Sec-tion2referencesexistingliteraturewhilecriticallyexamin-

2CriminalSpamActof2003(S.1293),SPAMAct(S.1231),

REDUCESpamActof2003(S.1327),WirelessTelephoneSpamProtectionAct(H.R.122),ReductioninDistributionofSpamActof2003(H.R.2214),CAN-SPAMActof2003(S.877),Anti-SpamActof2003(H.R.2515),ComputerOwners’BillofRights(S.563)