title: Le rôle des réseaux sociaux dans la géographie de l’innovation et de la collaboration : Trois essais
text: g.K a r l s ruh e ).Inc on t r a s t,r e g i on sth a tm a yb es t r on g lyemb edd ed ( i. e.h i ghp a r t i c ip a t i onin t en s i t y )m a ysh owl owop enn e s sandd iv e r s ifi c a t i ono fl ink s,thu s y i e ld in gl ow e rc en t r a l i t yv a lu e s( e. g.Î l ed eF r an c e ).H en c e,ar e g i on ’ sou tw a rdo r i en t a t i on andth ed iv e r s ifi c a t i ono fi t sn e tw o rkl ink sm od e r a t e sth einflu en c eo fr e g i on a ls c a l eon n e tw o rkc en t r a l i t y. Th i si sa m a j o rs t r en g tho fth em e a su r ep r opo s edinth i ss tudy,and i tp a v e sth ew a yf o rfu tu r es tud i e st oex am in eth er o l eo fc e r t a inr e g i on sinn e tw o rk so f in t e r r e g i on a lkn ow l ed g efl ow s. V i ew in gn e tw o rkpo s i t i on in go fr e g i on sint e rm so fr e g i on a lb r id g in gc en t r a l i t ym i gh tfu r th e re l ev a t eou rund e r s t and in go f wh i chr e g i on sa r e th em o s tc en t r a l,sh owh i ghv i s ib i l i t yanda tth es am et im ea r em o s timpo r t an tf o rth e n e tw o rkandth ein t e r r e g i on a ld iffu s i ono fkn ow l ed g e. F u r th e rm o r e,th eb r id g in gc en t r a l i t ym e a su r em a yc on t r ibu t et oth ed ev e l opm en to f a mu l t i -d im en s i on a lt ypo l o gyo fr e g i on s,b a s edons t ru c tu r a ln e tw o rkc r i t e r i aa c c o rd in g t oth e i rl ev e l so femb edd edn e s s,op enn e s sandd iv e r s ifi c a t i ono fl ink sinin t e r r e g i on a l n e tw o rk s.Su chat ypo l o gy m i gh tenh an c eou rund e r s t and in go fh owd iff e r en tth er o l e so f r e g i on s inn e tw o rk sm i gh tb e,andh owth eyc on t r ibu t et oth ea r r an g em en tandev o lu t i ono f th ein t e r r e g i on a ls t ru c tu r e. Th i si son eo fou rm a inpo in t sf o rafu tu r er e s e a r cha g end a. M o r e o v e r,i ts e em sn a tu r a lth a tanapp l i c a t i ono fth eb r id g in gc en t r a l i t ym e a su r eon o th e rt yp e so fkn ow l ed g en e tw o rk sa c c o rd in gt od iff e r en tt e chn o l o g i c a lfi e ld sm i gh tr ev e a l in t e r e s t in gp a t t e rn so fth em o s tc en t r a ln e tw o rkn od e s.H en c e,th em e a su r eo fb r id g in g c en t r a l i t yi sn o tl im i t edt oth ec on t ex to fR&Dc o l l abo r a t i on sbu tm a yp r o v et ob eu s e fu l a l s of o rth eapp l i c a t i onino th e rt yp e so fn e tw o rks t ru c tu r e s,su cha sin t e r r e g i on a lt r ad e fl ow so rin t e r r e g i on a le c on om i cv a lu ech a in s,a l s or e g a rd in gth e i rev o lu t i ono v e rt im e. 2.7 Append ix 2.7.1 Ob ta in ingthe B r idg ing Cen t ra l i ty A s sum eth a tth enumb e ro fa g en t so fr e g i oni,ni,andth enumb e ro fp r o j e c t so fth a tr e g i on, g,a r ep r opo r t i on a ls oth a tni
  
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  Th enth eb r id g in gc en t r a l i t yc anb er ew r i t t ena s i f o l l ow s : 7 3 BCi = = i ENBj k j =ik=i, j g g i j ik α g i j =ik=i, j   11   g g = i j ik αg ij =i k=i, j = 11 g ḡ ) i j( i−g i j αg ij =i = 2 1ḡ 2 i 1 − g i j αg g i ij =i  = 2 1ḡ i αg i 1− j =i  2 g i j  ḡ i 1 = ḡ s 1−hi) i i( α F u r th e r,a sth eαi sc omm ont oa l lr e g i on s,w el o s en og en e r a l i t yt os e t t in gi tt oα=1. Wh i chy i e ld sth er e su l
  
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Th el i t e r a tu r esu g g e s t sth eya r ea tp l a yinth eth r e et yp e so fm e ch an i sm sth a t g r ounda g g l om e r a t i one c on om i e s( sh a r in g,m a t ch in gandkn ow l ed g esp i l l o v e r s,a c c o rd in g t oth ec l a s s ifi c a t i ond ev e l op edb yDu r an t onandPu g a( 2 0 0 4 ) ).Sh a r in g :L o c a lc omp an i e s a r el ik e lyt ob en efi tn o ton lyf r omsh a r in gl a r g e rl o c a lp r odu c t i onf a c t o rm a rk e t s,bu ta l s o f r omsh a r in gd en s e rs o c i a lc onn e c t i on sb e tw e ena g en t sonth ef a c t o rsupp lys id e.S o c i a l n e tw o rk sa r ekn ownt of a c i l i t a t eth ec i r cu l a t i ono fin f o rm a t i ononth ea v a i l ab i l i t yo fj ob s ( G r an o v e t t e r,1 9 7 3 ;C a lv ó -A rm en g o landZ en ou,2 0 0 4 ),inp a r t i cu l a rf o rfind in gh i gh ly r an o v e t t e r,1 9 9 5 ).C on c e rn in gth ec ap i t a lm a rk e tf a c t o r,in t e r ind iv idu a l qu a l ifi edj ob s(G n e tw o rk sa r ea l s okn ownt ob ec ru c i a ld e t e rm in an t so fth esynd i c a t i onb eh a v i ou rinth e v en tu r ec ap i t a lbu s in e s s(S o r en s onandS tu a r t,2 0 0 1 ). M a t ch in g :J obs e a r ch m od e l s su g g e s tth a tin t e rp e r s on a lr e l a t i on sm a yr edu c eth ec o s t so fa cqu i r in gin f o rm a t i onon po t en t i a lm a t ch e sandin c r e a s eth equ a l i t yo fm a t ch e s.H an ak ie ta l.( 2 0 1 0 )sh owth a t in v en t o r swh oh adp r o f e s s i on a lr e l a t i on sw i thth eemp l o y e e so fh i s /h e rn ewemp l o y e ra r e m o r ep r odu c t iv eandh a v el on g e rt enu r e.In t e rm ed i a r i e sinth en e tw o rk m a ya l s op l a y th er o l eo fr e f e r en c ep e r s on sth e r eb ym i t i g a t in gin f o rm a t i ona symm e t ryp r ob l em sp r i o r t oth em a t ch e s( M on t g om e ry,1 9 9 1 ). 7 5 andth e r eb yg a ininb e in gimp r o v edandc omb in ed w i tho th e rsu g g e s t i on s. Kn ow l ed g e sp i l l o v e r sinl o c a len v i r onm en t sn e a r lya lw a y sin v o lv en on -m a rk e ts o c i a lr e l a t i on sth r ou gh wh i chkn ow l ed g ea c tu a l lyd iffu s e s.1 H ow ev e r,C a r l in oand K e r r( 2 0 1 5 ),wh or ev i ews tud i e sona g g l om e r a t i onandinn o v a t i on,a r gu eth a t“ th e r ei sv e ryl i t t l ein s i gh tin t oh owkn ow l ed g ei st r an sm i t t edam on g ind iv idu a l sl iv in ginc l o s eg e o g r aph i cp r o x im i t y.P r e sum ab lyth i so c cu r sth r ou ghbo th p r o f e s s i on a lands o c i a ln e tw o rk s,bu tth i sh a sn o tb e enc onfi rm ed ”(C a r l in oand K e r r, 2 0 1 5 ). ,2 0 0 7 )and( L oboandS t rum sky,2 0 0 8 ),b a s edonn e a r lyid en t i c a l USp a t en td a t a f r omth el a t es ev en t i e st o2 0 0 2. Th eyr e g r e s s,a tth e MSAl ev e l,p a t en t sc oun t sa g a in s t n e tw o rkv a r i ab l e sbu i l tu s in gc o in v en t i onp a t t e rn sando th e rc on t r o l s.B o ths tud i e sfind in g sa r es om ewh a tn e g a t iv ec on c e rn in gth einflu en c eo fp r o f e s s i on a ln e tw o rk sonr e g i on a l inn o v a t iv ep e r f o rm an c ewh i l em o r et r ad i t i on a la g g l om e r a t i onf e a tu r e sp r o v et ob e mu ch m o r er e l a t edt oinn o v a t i on. Inth i ss tudy,w ea ima tr e a s s e s s in g wh e th e rin v en t o r sn e tw o rk sd of a v ou rr e g i on a l inn o v a t i on,andi fs o,h ow. Bu i ld in gonth el i t e r a tu r eonn e tw o rkc en t r a l i t y( K a t z,1 9 5 3 ; B on a c i ch,1 9 7 2 ;B r inand P a g e,1 9 9 8 ;B a l l e s t e re ta l.,2 0 0 6 ),w ep r opo s es imp l eand fl ex ib l em i c r o f ound a t i on s,c on c ep tu a l i z in gh owin v en t o r sp r odu c t iv i t yc anb eaff e c t ed b yth e i rn e tw o rko fs o c i a lc onn e c t i on s. Th i sm od e lc on t a in sth r e ek eyin g r ed i en t sth a t w i l lb et e s t edinth eemp i r i c a lp a r to fth ech ap t e r :c onn e c t iv i t y,c omp l em en t a r i t yand r iv a l ry.C onn e c t iv i t yi sth em o s tb a s i ca s sump t i on.I ts t a t e sth a tin v en t o r sp r odu c t iv i t y i s(h ypo th e t i c a l lypo s i t iv e ly )aff e c t edb yc onn e c t i on st oo th e rin v en t o r s.C omp l em en t a r i t y po s i t sth a tanin v en t o reff o r t s ’p r odu c t iv i t yd ep end spo s i t iv e lyonth eeff o r t sth a th i s /h e r p a r tn e r spu tin t okn ow l ed g ep r odu c t i on. Th i sa s sump t i onc ap tu r e sth eid e ath a ta l lp a r t n e r sa r en o tth es am e :m o r ea c t iv en e i ghbou r sa r ec on t r ibu t in gm o r et oe g o ’ sin v en t iv e p r odu c t iv i t y.R iv a l rypo s i t sth a tth eb en efi ton ec and r awf r ome a chc o l l abo r a t i oni sin v e r s e lyr e l a t edt oth enumb e ro fc onn e c t i on so fth a tp a r tn e r. C on s equ en t ly,r iv a l ryimp l i e sth a tn ewc onn e c t i on sin cu rs om el o c a ln e g a t iv eex t e rn a l i t y. A sw ew i l lsh owinth i sch ap t e r,th i sv e rys imp l es e t -upimp l i e sth a t,a tth eequ i l ib r ium, in v en t o r sp r odu c eeff o r t sth a ta r ep r opo r t i on a lt oth e i rc en t r a l i t yinth en e tw o rk( a sin B a l l e s t e re ta l.,2 0 0 6 ). Th ef o rmo fn e tw o rkc en t r a l i t yimp l i edb yth em od e li sn ewanden c omp a s s e sex i s t in gc en t r a l i t ym e a su r e sa ssp e c ifi cc a s e s,su cha sth eD e g r e e,th eB on a c i ch andth eP a g e -R ank. Th em a inch a r a c t e r i s t i co fth i sc en t r a l i t ym e a su r ei sth a ti ti sru l ed 1O th e rw i s e,know l edg e maya l sob et ran s f e r r edth rough ma rk e tt ran sa c t ion s( e.g. loba r mob i l i ty, sp e c i a l i z edbu s in e s ss e rv i c e s ),bu tth enn e tw o rk sa r eba ckin toth ep i c tu r eth rough ma t ch ing m e chan i sm s ( P o r t e r,1 9 9 0). 7 6 b yth ech o s enl ev e l so fc onn e c t iv i t y,c omp l em en t a r i t yandr iv a l ry, wh i ch w i l le s t im a t ed inou remp i r i c a lex e r c i s e,h i gh l i gh t in gh own e tw o rk sp r e sum ab lyaff e c tinn o v a t i on. In p a r t i cu l a r,c omp l em en t a r i t yin c r e a s e sth eimpo r t an c eo fb e in gd i r e c t lyc onn e c t edt om o r e c en t r a la g en t sinth en e tw o rkandth e r e f o r ec ap tu r e sth epo s i t iv eeff e c to fb e in gc onn e c t ed t os t a r sinth en e tw o rk. Ou remp i r i c a lev id en c ei sb a s edonp an e ld a t ao fn e a r lyon ehund r edth ou s andF r en ch in v en t o r sandth e i rc o l l abo r a t i on sf o rth ep e r i od1 9 8 1 2 0 0 3p r ev i ou s lyc l e an ed,d i s am b i gu a t edand m a t ch ed w i thc omp an ym and a t o rysu rv ey sd a t a(C a r a y o le ta l.,2 0 1 5 ). Th ean a ly s i si sc a r r i edou ta tth er e g i on a ll ev e l,id en t ifi edb yF r en chemp l o ym en ta r e a s (EA s ),c omb in edt os ev ent e chn o l o g i c a lfi e ld s. Ou rm i c r o f ound ed m e th od o l o gya l l ow s u st or e f r a inf r omr e g r e s s in gr e g i on a lp e r f o rm an c eons ev e r a ln e tw o rks t a t i s t i c s( o f t en h i gh lyc o r r e l a t ed )inanad -h o cm ann e r. W ee s t im a t ea m od e linwh i chth efu tu r ep a t en t e chn o l o gyi safun c t i ono fth ea v e r a g en e tw o rk p r odu c t i ono fag iv enemp l o ym en ta r e a×t c en t r a l i t yo fth ein v en t o r so fth i sEA t e chn o l o gy. Th es t ru c tu r eo fth ed a t aa l l ow su st o in c lud eav a r i ou ss e to fc on t r o l ssu cha sEA t e chn o l o gyandt im e t e chn o l o gyfix edeff e c t s. Th er e su l t ssh owth a t,fi r s to fa l l,th ein v en t o r sp r odu c t iv i t ya r eind e edpo s i t iv e ly aff e c t edb yth e i rc onn e c t i on sinth en e tw o rk( c onn e c t i v i t y) :in v en t o r s ’c en t r a l i t yh a sa po s i t iv einflu en c eonr e g i on a linn o v a t i on. Th i sfi r s tr e su l td em on s t r a t e sth a tth ec o l l ab o r a t i onn e tw o rko fin v en t o r sa r en o tju s tequ i l ib r iump r op e r t i e sth a tw ou ldb esh ap edb y o th e rph y s i c a l,s o c i a lo re c on om i cc ond i t i on s. Ou rs e c ond m a inemp i r i c a lr e su l ti sn e g a t iv e,inth a tw efindn oev id en c eo fr iv a l ry inth ew a yn e tw o rk ssu s t a ininn o v a t i on. Th i sfind in g, wh i chi sr obu s tt oal on gl i s to r r obu s tn e s sch e c k s,i sinsuppo r to fanin t e rp r e t a t i ono fth en e tw o rkb en efi t sint e rm so f d iffu s i onandc on t a c tr a th e rth anint e rm so fsh a r edt im eandeff o r t sinc omm onp r o j e c t s (wh i cha r er iv a l ). On eimp l i c a t i oni sth a tn e tw o rkc onn e c t i on sd on o timp lyan yn e g a t iv e ex t e rn a l i t yonn e i ghbou r s. Th eth i rd m a inr e su l t,a l th ou ghl e s ssy s t em a t i c,suppo r t sth a t th e r ei ss om ec omp l em en t a r i t yeff e c ta tp l a yinth en e tw o
  
  rk. Th en ex ts e c t i onr ev i ew sth el i t e r a tu r eonc o l l abo r a t i onandth eb en efi t sp r o v id edf r om th en e tw o rka tth ein v en t o randa tth er e g i on a ll ev e l.S e c t i on3. 3p r e s en t sth em od e lwh i ch l ink sin v en t o r s ’p r odu c t iv i t yt oth e i rn e tw o rk. Th ed a t a,v a r i ab l e sandth ee c on om e t r i c s t r a t e gya r ed e s c r ib edinS e c t i on3. 4. Th er e su l t sa r ep r e s en t edinS e c t i on3. 5. Th el a s t s e c t i onp r o v id e sc on c lud in gr em a rk s. 3.2 Why wou ldinv en to r s ne two rk s ma t te rfo rre g iona linnov a t ion
  
  Inth i ss e c t i on,ou rob j e c t iv ei st oexp l a inwh yandh owin v en t o r sn e tw o rksh ou ld m a t t e r f o rr e g i on a linn o v a t iv en e s s. R e s e a r ch e r sh a v eh i gh l i gh t edth eimpo r t an c eo fl o c a l i z ed kn ow l ed g efl ow sa sc ru c i a ld r iv e r so fl o c a lin v en t iv i t y. Th i si sa l s oc on s i s t en tw i tha s t r on ga s sump t i on m ad eine c on om i cg e o g r aph ya c c o rd in gt owh i chkn ow l ed g esp i l l o v e r s g r oundth ef o rm a t i ono findu s t r i a landinn o v a t iv ec lu s t e r s(S e c t i on3. 2. 1 ). Kn ow l ed g e fl ow sth r ou gh(v a r i ou s )in t e rp e r s on a lr e l a t i on so fr e s e a r ch e r sand / o ren g in e e r s,wh i cha r e e s s en t i a l lyt i edn e a rb y(S e c t i on3. 2. 2 ).F in a l ly,th e r ea r em an yr e a s on st oth inkth a t,a san " in v i s ib l ec o l l e g e "o fa c ad em i cr e s e a r ch e r sex i s t,c ommun i t i e so fin v en t o r sw ou lda c c oun t f o rin v en t iv en e s s.P a r ad o x i c a l ly,th ef ews tud i e sth a th a v es ou gh tt or ev e a lth i sinflu en c e a r en o tc on c lu s iv e(S e c t i on3. 2. 3 ). 3.2.1 Agg lome ra t ion,know ledgesp i l lov e r sandreg iona linnov a t ion
  
  Wh a texp l a in sth einn o v a t iv en e s so far e g i on? Afi r s tr e spon s ec anb eind i r e c t lyf ound a r sh a l l( 1 8 9 0 ),f o l l ow edb yJ a c ob s( 1 9 6 1 )andJ aff e( 1 9 8 6 ), wh od e s c r ib edth r e e inM r e a s on sf o rwh i chp r odu c t iv ea c t iv i t i e st endt oc lu s t e rinsp a c e :th ep r o x im i t yt od ed i c a t ed supp l i e r sands e rv i c e s,th ep r e s en c eo fal ob a rm a rk e tpoo l in gandth eex i s t en c eo fl o c a l i z ed kn ow l ed g esp i l l o v e r s. Th o s eb en efi t st oa g g l om e r a t i ons e emt op l a yfu l lyf o rinn o v a t i on a c t iv i t i e ss in c ei th a sb e enp r o v edin m an yw a y sandind iff e r en tc on t ex t s(n a t i on a l, s e c t o r a l )th a tinn o v a t iv e(R&D )a c t iv i t i e sandinn o v a t i on sa r eev en m o r ec on c en t r a t ed th ana r em anu f a c tu r in gindu s t r i e s( e. g.,Aud r e t s chandF e ldm an,1 9 9 6 ;C a r r in c a z e aux,2 0 0 1 ;Bu z a rdandC a r l in o,2 0 1 3 ). e ta l. R e c en t ly,C a r l in oand K e r r( 2 0 1 5 )su rv eyth e o r e t i c a lm od e l sex am in in gh owth e s e r an t onandPu g a( 2 0 0 4 )t ax on om y, m e ch an i sm sc ou ldop e r a t ef o rinn o v a t i on.U s in g Du th eys e tth er e a s on s wh ysh a r in gc omm oninpu t s( su cha ssk i l l edl abou r,sp e c i a l i z ed bu s in e s ss e rv i c e s,en t r ep r en eu r i a lfin an c e ),b en efi t in gf r oml abou rm a rk e tpoo l in g(wh i ch imp r o v e sth equ a l i t yo fm a t ch e sandth em ob i l i t yo fw o rk e r s )andf r oml e a rn in g( th ank st o 7 8 l o c a lin f o rm a t i ond iffu s i on )a r ee a chr e l ev an tf o rinn o v a t iv ea c t iv i t i e s. Un f o r tun a t e ly,th e emp i r i c a lid en t ifi c a t i ono fth eou t c om eo fe a cho fth e s em e ch an i sm sint e rm so fkn ow l ed g e g en e r a t i oni sp r ob l em a t i candind e ed,th e r ei sas ev e r el a c ko femp i r i c a lev id en c eonth e s e i s su e s( C a r l in oandK e r r,2 0 1 5 ). Am on gth o s em e ch an i sm s,kn ow l ed g esp i l l o v e r sa r eo fc r i t i c a limpo r t an c einexp l a in in g l o c a lc r e a t iv i t yandinn o v a t i on. Th i sh a sb e ena l s opo in t edou tin N ew G r ow thTh e o ry m od e l s,wh i chemph a s i z eth er o l eo fkn ow l ed g efl ow sa sc ru c i a ld r iv e r so fe c on om i cg r ow th ( e. g.Lu c a s,1 9 8 8 ;R om e r,1 9 9 0 ).Inp a r a l l e l,abund an temp i r i c a lev id en c e s,m o s t lyr e ly in g onkn ow l ed g ep r odu c t i onfun c t i on s,h i gh l i gh tth a tsu chkn ow l ed g esp i l l o v e r sa r esp a t i a l ly andt e chn o l o g i c a l lybound ed( s e eJ aff e,1 9 8 6 ;An s e l ine ta l.,1 9 9 7 ;O r l and o,2 0 0 0 ;Au t an t B e rn a rd,2 0 0 1 ;F e ldm an,1 9 9 9,f o rar ev i ew ).J aff ee ta l.( 1 9 9 3 )o rA lm e id aand K o gu t ( 1 9 9 7 )h a v et ak enad iff e r en tr ou t et oex am in eh owkn ow l ed g efl ow sinsp a c e,u s in gp a t en t s d a t a. Th eyu s ep a t en tc i t a t i on st ot r a c eth efl ow so fkn ow l ed g ef r omon ein v en t i ont o an o th e r. Th eyc ompu t eandc omp a r eth ep r ob ab i l i t i e so fp a t en t sc i t in gp r i o rp a t en t sw i th in v en t o r sf r omth es am em e t r opo l i t ana r e aa g a in s tar and om lyd r awnc on t r o ls amp l eo f c i t edp a t en t s. 3.2.2 Inv en to r s ’re la t ion sh ip sv s.co loca t ion
  
  I fkn ow l ed g esp i l l o v e r sm a in lyo c cu rl o c a l ly,id e a sa r en o tc i r cu l a t in g“ inth ea i r ”.E s p e c i a l lywh enc omp l ex,t a c i to radv an c ed,th e i rd iffu s i onimpo s ein t e rp e r s on a lr e l a t i on s b e tw e enr e s e a r ch e r sand / o ren g in e e r s wh i ch m a ysp anfi rmo rin s t i tu t i on sbound a r i e s F l em in gand M a rx,2 0 0 6 ).A c c o rd in gt oS ax en i an( 1 9 9 6 ),th o s er e l a t i on sa r eo f t enin ( f o rm a l. M o r e o v e r,th eS i l i c on V a l l ey w a sch a r a c t e r i z edb yah i gh m ob i l i t yo fw o rk e r s a c r o s sc omp an i e s. Th i sl ed,a tl e a s tp a r t ly,t oasup e r i o randl a s t in ginn o v a t iv ep e r f o rm an c eo fth i sr e g i on,c on t r a s t in gw i thth ed e c l in eo fth eB o s t on -R ou t e1 2 8c lu s t e r. Thu s c o l o c a t i oni son lyp a r to fth es t o ry :th i sh a sb e enp r o v en m o r esy s t em a t i c a l lyth ank s t oth ea v a i l ab i l i t yo fp a t en t sandpub l i c a t i on sd a t a wh i ch m ak e( a tl e a s tinp a r t )v i s ib l ebo thth e s efl ow so fin f o rm a t i on,th r ou ghc i t a t i on s,ando fc o l l abo r a t i on sb e tw e en in v en t o r s,th r ou ghc o -p a t en t in go rc o -pub l i c a t i on.B r e s ch iandL i s s on i( 2 0 0 3 )andS in gh ( 2 0 0 5 ),r e sp e c t iv e lyf o rUSandEu r op e anin v en t o r s,sh owth a tin t e rp e r s on a lc onn e c t i on s a r eth esuppo r to fsu chkn ow l ed g esp i l l o v e r sandth a tkn ow l ed g efl owd e c r e a s e ssh a rp ly w i ths o c i a ld i s t an c e. Th e s eau th o r sf oundth a tb e in gl o c a t edinth es am ea r e ah a sl i t t l e o rn o tsupp l em en t a ryimp a c tonth ep r ob ab i l i t yo fkn ow l ed g efl owb e tw e enin v en t o r sth a t a l r e adyh a v ec l o s en e tw o rkt i e s. Ind e ed,i ttu rn sou tth a t in v en t o r s ’r e l a t i on sh ip sa r em a in lyt i ed l o c a l ly.U s in gEu r op e an a r a y o landR oux( 2 0 0 7 )an a ly s eth eg e o g r aph i cd i s t an c es ep a r a t in gin v en t p a t en td a t a,C 7 9 o r s wh oc o in v en tap a t en t. Th eyf oundth a tm o r eth an7 5%o fsu chc onn e c t i on sa r e a ch i ev edb e tw e enin v en t o r sth a tl iv ea tl e s sth an5 0kmf r ome a cho th e rwh i l el e s sth an 4%o fth ec onn e c t i on sa r ef o rm edb e tw e ena g en t swh ol iv ea tm o r eth an5 5 0kmf r ome a ch 2 o th e r. On eexp l an a t i oni sl ink edt oth ec o s t so fm a in t a in in gc onn e c t i on swh i chw ou ld in c r e a s ew i thd i s t an c e :c l o s e lyl o c a t ed a g en t sin cu rl ow e rc o s t st oe s t ab l i shc ommun i c a t i on sandt oc oo rd in a t e,int e rm so ft r an spo r t in gc o s t sandt im e.