绘制美国活动中心的地图（英）.docx

OCTOBER2022BBrookingsMetroANNETANORoeUUHBASSCENTER11MTRANSFORMATIVEP1.ACEMAKIMOMAPPINGAMERICAjSACTIVITYCENTERS:THEBUI1.DINGB1.OCKSOFPROSPEROUS,EQUITAB1.E,ANDSUSTAINAB1.EREGIONSTracyHadden1.oh,DWRowlands,AdieTomer,JosephKane,andJenniferVeyCONTENTIntroduction3Whydoesthegeographyofactivitymatter?5Whatareactivitycenters?7Ourmethodology8Keyfindingsfromouractivitycenteranalysis13Finding1:Activitycentersaremoreactive,containinganoutsizedshareofmetropolitanassets13Finding2:Activitycentersaremoreproductive,withgreaterdensityleadingtohighergrossmetropolitanproduct16Finding3:Activitycentersaremorevaluable,withhighercommercialandresidentialrealestateassessments17Finding4:Activitycentersaremoreaccessibleandinclusivetometroarearesidents18Finding5:Activitycentershavemoresustainabletraveloutcomes,withlessdrivingandmorewalkingandbiking22Implicationsforpractice25Implication1:Nurturingaproductive,innovativeeconomicecosystem25Implication2:Supportinganaccessible,flexible,andsustainablebuiltenvironment26Implication3:Fosteringaninclusiveandequitablesocialenvironment26Implication4:Encouragingalocallyorganizedcivicinfrastructure26Conclusionandareasforfutureresearch27Acknowledgements28IntroductionAsthesayinggoes,threethingsmatterinrealestate:location,location,location.Citiesandmetropolitanareasarebuiltaroundassetssuchastransportationnodes,employmenthubs,culturalattractions,politicalandreligiousinstitutions,andhealthfacilitiesallofwhichtendtoclusterinspecificlocations.Theabilitytodeveloptheplacesthatconcentratetheseassetshasalwaysbeenakeyingredienttobuildingproductiveandthrivingmetroareas.Butafterdecadesofsuburbanization,activitydoesnotconcentrateinthesamewaysitoncedid.Metropolitanareasarenolongerstructuredalongalinearcontinuum,fanningoutwardfromadistinctdowntowntoedgelesssuburbiatoruralcountrysidedottedwithafewtowncenters.Theyinsteadcontainconstellationsofasset-richplaces,typicallysurroundedbyhousing-onlydevelopmentsoramixofresidentialandcommercialsprawl.1Thislong-standingconceptofmetropolitangeographyasalinefromasingularurbancentertosuburbstofarms-andconceivingofthesuburbsasexclusivelyresidentialplacesisnolongeraccurateintheageofAmericanmegaregions.Overtime,thedispersionofassetsandactivitieshasstretchedthedistancesbetweenpeopleandopportunity,oftenleadingtogreatereconomicandracialinequality.2Morerecently,theemergenceofrapidtelecommunicationsandaglobalpandemichaveledtonewuncertaintiesaboutwhatkindsofplaceswillbeindemandinthefuture.Atatimewheneconomicandclimate-relateddisruptionsseemtocomeevermorefrequently,itiseasytolosetrackofthefactthatthebuiltenvironmentchangesquiteslowly.Assuch,industrial,cultural,andenvironmentalshiftsinthedecadestocomewillprimarilyoccurwithinexistingplacesandalongsidetheinfrastructurewe,vealreadycreated.But,asinthepast,theimpactsofthoseshifts-forgoodandforill-willstillbeinfluencedbythechoiceswemaketodayregardinghowandwhereweprioritizefutureinvestments.Allthismakesitessentialthatthefieldofmetropolitandevelopmentparticularly,practitionersandappliedresearchershasacontemporaryunderstandingofwhatpeopleandtheeconomyneedfromplace,howthoseneedsexpressthemselvesonthelandscape,andhow,then,thefieldshouldrespondtothem.Inotherwords,weneedtoestablishbothanewmapandanewvocabularyforAmericaneconomicgeography.Onemajorobstacleisthatthereisnoconsistentschemetocomparewhereactivityconcentrateswithinmetropolitanareasorwhatkindsofplaceswithwhattypesofattributes-canbestsupportsharedprosperityandresilience.Inthisreport,weintroduceanewmethodologytolocateandcharacterizeactivitycenters:placeswithinregionswhereeconomic,physical,social,andcivicassetsclusterataclearlydefinedhyperlocalscale.3Wepresentatypologyofactivitycenters,maptheirlocationswithinthe110U.S.metropolitanstatisticalareas(MSAs)withatleast500,000residentsusingcensusblockgroups,andanalyzethosecenterstohelpplanners,realestateprofessionals,andelectedleadersbetterunderstandhowandwhytheymatter.Wefindthat: Metropolitanareasconcentrateassetsinactivitycenters.Withinthemetropolitanareasinourstudy,activitycentersoccupyjust3%ofallland,yetholdafarhighershareofassetsandtheirassociatedactivities.Forexample,40%ofallprivatesectorjobslocatewithinactivitycenters,andinstitutionalassetsincludingcollegeanduniversitystudents,hospitalbeds,andmajorintercitytransportationnodesarealmostexclusivelyfoundintheseareas. Metropolitanareasthatconcentratejobsinactivitycentersaremoreproductive.Ouranalysisrevealedaclearandpositiverelationshipbetweenactivitycenterjobdensityandproductivity,asmeasuredbygrossmetropolitanproduct(GMP)perworker.Every1,000jobspersquaremileinametroarea'smedianactivitycenterwasassociatedwithanadditional$11723inoutputperworkeracrossthemetroarea. Activitycentersyieldavaluepremium.Activitycentershavefourtimesthecommercialrealestateassessedvaluerelativetodevelopedlandarea.Fortwo-thirdsofmetroareas,housingnearactivitycentersisworthaweightedaverageof26%more.Inthreehigh-growthmetroareas(Raleigh,N.C.,Deltona,Fla.,andtheWashington,D.C.area)thesehousingpremiumsexceed50%. Activitycentersaremoreaccessibleandinclusive.Thevastmajorityofmetropolitanresidentsinthevastmajorityofmetroareas一livewithin3milesofanactivitycenter,andthisisevenmoretrueforpeopleofcolorandlow-incomehouseholds. Activitycentershavemoresustainabletraveloutcomes.Theseareasarereachablebytwiceasmanybusandtrainridersasotherblockgroups.Activitycentersthemselveshavehigherwalkabilitythantheirmetroareasasawhole,whichcontributestothefactthatbothcommuteandnon-commutetripsbycarareshorterwhenstartinginactivitycentersversusotherplaces.Thispaperrepresentsacriticalstepinhelpingplannersandotherpractitionerscompareactivitycentersacrossdifferentmetroareas.Intheprocess,thefindingsmakethecasetobuildonexistingassets(bothliterallyandfiguratively)wheneverpossible,ratherthanprioritizinglow-densityand/orsingle-usedevelopment.Itconcludesbypointingtohowleaderscanusethisinformationtoadvancetransformativeplacemakingwithinactivitycentersandbydoingso,increaseregionalcompetitiveness,enhancesustainabilityandresilience,andimprovethesocialandphysicalwellbeingofallmetroarearesidents.4Whydoesthegeographyofactivitymatter?Metropolitanareasaredesignedtosupportactivity.TheyhouseanoutsizedshareoftheAmericanpopulation,andtheirindustriesgenerateanevengreatershareofeconomicoutput.5Metroareasarethesitesforclustersofculturalassets,educationalinstitutions,andgovernmentoperations.6Theyarealsologisticshubsfortheuntry,stradeingoods,andtravelcentersfortouristsandbusinesspeople.7Datapointafterdatapointaffirmshowmucheconomicandsocialactivityconcentratesinourmostpopulatedareasofthecountry.Yettheshapeofmetropolitanactivityisnotconsistent.Demandsforindustrialandcommercialland,housingpreferencesamongresidents,consumertastesforretailandrecreationalamenities,andevennaturaltopographyarejustsomeofthemajorfactorsthatinfluencepreciselywhereallthosemetropolitanactivitiestakeplace.Thesefactorshavehelpedcreateawide-rangingeconomicgeographyacrossmetropolitanAmerica.Somemetroareasusefarlesslandthanothers.Forexample,metropolitanPhiladelphiahas2.5%moreresidentsthanmetropolitanAtlanta,butthelattercovers88.6%moreland.8Meanwhile,evenwithinthesamemetroarea,it'scommontofindcompletelydifferentformssupportingthesamekindsoflanduses:Chicago'sautomobile-orientedsuburbsfunctionfardifferentlythantheolderneighborhoodswithinamileortwoofthe1.oop,thecity,sfamouscentralbusinessdistrict,eventhoughbothsupportresidential,commercial,andrecreationalactivities.9It'sunderstoodthatthesameactivitieswilllookdifferentinplaceswithdifferentgeographies.Thegeographicvariabilityofmetropolitanactivity,then,hasmajorimplicationsforhowmetroareasoperate,thepractitionerswhoguidetheirdevelopment,andtheresidentsandbusinesseswhocalltheseplaceshome.Existingresearchdemonstratessomeoftheseimplications.Forone,theshapeofactivitydirectlyimpactslocalandevenstatefiscalconditions.Dependingontaxpolicies,thelocationanddensityofindustrieswilldeterminewhichlocalgovernmentsllectincome,sales,andpropertytaxrevenuesandtherelativecollectionpotentialperacre.Therearesimilartaxconcernsformunicipalitiesthathostmajornonprofitinstitutionslikehospitalsoruniversities,whichmayattractsizableactivitybutgeneratereducedtaxrevenues.Ontheothersideoftheledger,metropolitangeographyinfluencesthepricetagassociatedwithprovidingmunicipalinfrastructure.Thecoststobuildandmaintainhighwaysaren'tthesameascommuterrailorsidewalks,andpublicwaterutilitiesorprivateenergyandbroadbandcompanieswillhavedifferentinvestmentneedsbasedonthedensityofdevelopment.Finally,patternsofconcentrationand/ordispersionimpactthesizeandviabilityofmarkets,whichaffectsemployersandretailersintermsoftheircosts,revenuepotential,andultimately,thepayrollandsalestaxestheygenerate.Thegeographyofeconomicactivityalsodirectlyimpactstheindustrialcompetitivenessofametroarea.Economistshavelongstudiedthepowerofagglomerationthetendencyofsimilarormplementaryfirmstolocateinclosephysicalproximitytogeneratepositiveeconomicreturnstotheimpactedfirmsandthesurroundingarea.10Concentratingactivitywithincertainneighborhoodscanproducegreatereconomicvaluebyfacilitatingcollaborativeresearchthatyieldsnewproductsandservices;italsolowerscostsbyfacilitatingthesharingofinputslikefreightneedsoraccesstoacommonlaborpool.11Densityandproximitycanalsogeneratemoreinnovation:A2017Brookingsreportshowedthat,onaper-studentbasis,researchuniversitieslocatedinthedowntownsofthe100largestU.S.citiesreceived120%morepatentsandspunoff70%morestartupsthanresearchuniversitieslocatedinsmallertowns,suburbs,orruralareas.12Environmentalconditions,too,areaffectedbythespatialpatternsofactivity.Sprawlingneighborhoodsandmetroareastendtogeneratehighervehiclemilestraveledperpersonthanhigher-densityareas,leadingtomoregreenhousegasemissionsandmoredangeroustransportationsystems.13Moreover,buildingsthatarefurtherapartandlowerinheighttendtousemoreenergyperperson.141.ow-density,autocentricdevelopmentpatternsarealsoassociatedwithothernegativeecologicalimpacts,includinggreaterstormwaterrunofffromimpervioussurfacesandlossofnaturalhabitatsfromurbanlanddevelopment.15Putallthistogether,anditisclearthatwhereandhowdevelopmentoccurshasaprofoundinfluenceoneconomicequityandinclusion.Fiscallystableregionscaninvestmoreinpublicgoods-fromschoolstoparksthatbenefitchildrenandfamilies.Moreeconomicallycompetitiveregionsgrowandattractjobsrequiringvaryingskillsandeducationallevels;whenthosejobsaremoreproximatetowherepeoplelive,transportationcoststhesecond-highestexpenseformanyhouseholdsarelower.16Andmoresustainableregionsarelesspronetothehealth,safety,andeconomicimpactsofenvironmentaldisastersandclimatechange,towhichlow-incomeneighborhoodsandpeoplearemostvulnerable.Theextenttowhichinternalgeographycaninfluencemetropolitanareas'prosperity,resilience,andequityunderscorestheneedtotakeafreshlookathowandwhereactivityislocatedwithinthem-andidentifytheregionalactivitycenterswhereeconomic,physical,social,andcivicassetsmostclusterandconnect.Whatareactivitycenters?Whiletheirspatialpatternsofactivityvaryconsiderably,onthewhole,thevastmajorityofspaceinU.S.metropolitanareasischaracterizedbylow-intensity,segregatedlanduses.Today,onlyonein12peopleworkwithin2kilometers(-1.25miles)oftheirresidence;onlyoneinninejobsareincentralbusinessdistricts(CBDs);andjustoneinsevenjobsareinsubcentersoutsideCBDs.Threeinfourjobsareoutsideofemploymentcentersaltogether.17Yetamidallthisdispersionareplaceswherelarge,diversemixesofassetsconcentrate.Theseclustersvaryinsizeandshapeandplaydifferentrolesintheirrespectiveregionaleconomies.18Forexample,industrialandmanufacturingactivitiesstillclusteraroundfreightinfrastructure.19Publicadministrationofficesarestillconcentratedindowntowns.20Andastheknowledgeeconomyhasgrowninsizeanddominance,accesstospecializedtalent,thetransferoftacitknowledge,andincreasedproductivityfromknowledgespillovershaveledtotheincreasingconcentrationoffinance,technology,andresearchintensivejobsnotonlyincertainmetropolitanareas(e.g.,SanFrancisco),butinspecificneighborhoodswithinthem.21Together,theseindustryhubsarecreatingincreasingly,<polycentric,regionallandscapesanevolvingformofdevelopmentthatstandsincontrasttotheedgelesscitiesthatdominatedtheendofthe20thcentury.Overtheyears,planningpractitionersandresearchershavemadenumerouseffortstoidentifyandunderstandtheseconcentrations,andinsomecases,maptheirlocations.22However,theseplanningexerciseshavelargelybeenbasedonaverynarrowdefinitionoftheactivitythattakesplacewithinregionalclustersessentiallylimitingittosleeping(mappedashousing)andworking(mappedasjobs).Thisisareductivewayofvaluinghowpeoplespendtheirtime一andonewhichgivesaverydistortedpictureofthespatialpatternofAmericans'activity.In2019,full-timeemployedadultsspentanaverageof16.7hoursperweekdoingactivitiesinplacesotherthanworkandhome,whileadultspaidpart-timeornotatallspentover20hoursaweekontheseactivities.23Dataavailabilityonsometypesofactivityandcomparabilityofmeasuresofcentralityhavealsorestrictedtheexistingliterature.Thus,moststudieslimitanalysestooneorasmallsampleofmetropolitanareasandsub-areas.Forexample,theU.S.censusisareliablepublicsourceofinformationaboutthelocationofhousingatahyperlocalscale.Priorto2010,however,thecensusdidnotincludehyperlocaljobdatathus,pastresearchontheeconomicgeographyproducedbythesuburbanizationofjobssometimesusedabsolutethresholdsofcommercialrealestatesquarefootagetodefineplaces.Forexample,in“EdgeCity:1.ifeontheNewFrontier,authorJoelGarreauarguedthat'4densityisback"intheformofsuburbanemploymentcenterswithatleast1millionsquarefeetofofficespace.24InwEdgelessCities:ExploringtheElusiveMetropolis/'authorRobertE.1.angcounteredbyobservingthatthenatureofsprawlissuchthatifyoudrawabigenoughboundary,youcancatchenoughsquarefootagetohavesomethingtnotenoughtoconstituteatruesomewhere.25ChristopherB.1.einberger1SuTheOptionofUrbanism:InvestinginaNewAmericanDream"reframedthisdebateaboutscaleandgeographybydistinguishingbetweenwalkableanddriveablebuiltenvironments,whichcanbefoundinbothmetrocoresandatmetrofringes,definedastheendsofarangeofflr-to-arearatios.26InordertounderstandtheroleofplaceinthecontemporaryUnitedStates,weneedtofocusonspecificjobsectorsthatdocluster,andthenlookbeyondproductiontoincludeconsumption,housing,andothereconomicandsocialdimensionsthataffectpeople,stime,travel,andlocationdecisions.OURMETHODO1.OGYInthisreport,weidentifyblockgroupscontainingexistingactivitycentersusingasimpleandreplicablemethodologyforcombiningmultiplediversedatasourcesonthelocationsofactivitiesandassets.Comparableacrossmetropolitanareas,thisapproachprovidesamorestandardizedandcomprehensivewaytounderstandthelocalgeographyofactivitythanpreviousefforts.Forthisanalysis,weidentifiedfivecategoriesofassetsthatcancontributetoanareabeinganactivitycenter:community,tourism,consumption,institut