法国预测与国际信息中心-知识在空间中的渗透（英）-2024.7-45页

No2024-08–JulyWorkingPaperThePercolationofKnowledgeacrossSpacePierreCotterlaz&ArthurGuillouzouicHighlightsWeshowthatthenegativeeffectofgeographicaldistanceonknowledgeflowsstemsfromhowfirmsgainsourcesofknowledgethroughtheirexistingnetwork.Inaggregate,thedistanceelasticityofpatentcitationsflowshasremainedconstantsincethe1980s,despitetheriseoftheinternet.Atthemicrolevel,firmsdisproportionatelyciteexistingknowledgesources,andpatentscitedbytheirsources.Weintroduceamodelfeaturingthelatterphenomenon,andgeneratinganegativedistanceelasticityinaggregate.Whilethedistanceeffectshouldhavedecreasedwithconstantcountrycomposition,theriseofEastAsianeconomies,associatedtolargedistanceelasticities,compensatedlowerfrictionsinothercountries.CEPIIWorkingPaperThePercolationofKnowledgeacrossSpaceAbstractThispapershowsthatthenegativeeffectofgeographicaldistanceonknowledgeflowsstemsfromhowfirmsgainsourcesofknowledgethroughtheirexistingnetwork.Westartbydocumentingtwostylizedfacts.First,inaggregate,thedistanceelasticityofpatentcitationsflowshasremainedconstantsincethe1980s,despitetheriseoftheinternet.Second,atthemicrolevel,firmsdisproportionatelyciteexistingknowledgesources,andpatentscitedbytheirsources.Weintroduceaframeworkfeaturingthelatterphenomenon,andgeneratinganegativedistanceelasticityinaggregate.ThemodelpredictsPareto-distribut...