SMALL WORLDS IN NETWORKS OF INVENTORS AND THE ROLE OF SCIENCE: AN ANALYSIS OF FRANCE

FRANCESCO LISSONI (1), PATRICK LLERENA(2), BULAT SANDITOV(3) (1) Brescia University & KITeS – Bocconi University, (2) BETA – University of Strasbourg, (3) UNU-MERIT, Maastricht University

Background Sociology of science:

“Invisible colleges” (De Solla Price 1963, Crane 1972)“Weak links, small worlds and nodes are the most useful words for understanding the way that scientific discovery advances.”

(Francis Fukuyama, preface to The New Invisible College by C. Wagner) Small worlds” & innovation

Theory Cowan & Jonard (2003, 2004)

Empirical evidence: Uzzi & Spiro (2005) : Broadway musicals Schilling & Phelps (2007): Technology alliances Fleming et al. (2007), Breschi & Lenzi (2011): Co-invention

networks

What is this paper about? Structure of inventors’ networks in France:

Are they “small worlds” (tightly knit communities of inventors & few “shortcuts” between communities)?

Role of academics and CNRS researchers in inventors’ networks Do they contribute to “small-world” structure

(bridging distant communities of inventors)?

Data Sources EP-INV database (KITeS-Bocconi University)

Patent applications at EPO since 1978 reclassified by applicant and inventor

Subset of inventors with address in France KEINS database on academic inventors (Lissoni et al.

2006) Matching inventors with a list of university professors in

service in 2004. Verifying matches by contacting professors

Dataset on CNRS inventors (Llerena 2010) KEINS methodology CNRS researchers on duty in 2007

Science-intensity by Technological field - Academic & CNRS inventors/patents

TECHNOLOGICAL FIELDS INVENTORS PATENTS

All Acad+CNRS All Acad+CNRS

Electrical Eng. Electronics 13610 340 2.50% 18237 504 2.8%

Scientific Instruments 9714 541 5.57% 10164 658 6.5%

Chemicals. Materials 8653 595 6.88% 12157 1336 11.0%

Pharmaceuticals. Biotechnology 5980 676 11.30% 7346 1119 15.2%

Industrial processes 8159 250 3.06% 10043 290 2.9%

Mech. Eng. Machines. Transport 10386 86 0.83% 13796 113 0.8%

Consumer goods. Civil eng. 5158 17 0.33% 7057 24 0.3%

“Productivity” & Team size

TECHNOLOGICAL FIELDSProductivity Team Sizes

All A+C All A+C(obs.) Baseline

Electrical Eng. Electronics 3.12 3.22 2.01 3.06 2.70

Scientific Instruments 3.59 3.48 2.10 3.43 2.87

Chemicals. Materials 4.72 4.34 2.68 3.87 3.38

Pharmaceuticals. Biotechnology 4.12 3.09 2.51 3.68 3.20

Industrial processes 4.00 4.78 1.87 3.65 2.52

Mech. Eng. Machines. Transport 3.16 5.70 1.81 3.00 2.43

Consumer goods. Civil eng. 3.32 6.06 1.59 2.33 2.08

Inventors mobility across organizations

TECHNOLOGICAL FIELDS Non-academic inventors Acad. inventors CNRS inventors

Electrical engineering. Electronics 0.32 0.55 0.65

Instruments 0.32 0.59 0.60

Chemicals. Materials 0.28 0.56 0.57

Pharmaceuticals. Biotechnology 0.29 0.64 0.64

Industrial processes 0.28 0.58 0.57

Mech. Eng. Machines. Transport 0.31 0.49 0.52

Consumer goods. Civil eng. 0.28 0.42 0.75

Number of distinct applicants normalized by the number of inventor’s patents

NETWORK OF INVENTORSPatents

Inventors

Small worlds: Watts & Strogatz (1998)

•“Small world” networks:o sparseo clusteredo short distances

• WS model of SW:

Small-world ratio:Q=(Cobs/Сrg)/(Lobs/Lrg)

Clustering:C = [3 × #(/\)]/ #(/\)

Benchmark random graph (BRN)

Erdos-Renyi random graph is not an appropriate benchmark random structure for our networks. An inventor connects with the whole research

team (rather than with individual inventors)

Benchmark random graph (BRN): Keep number of number of inventors per patent

and number of patents per inventor, and randomly “rewire” patent-inventor links

Project bipartite graph onto the set of inventors

Observed networks vs. simulated benchmark random graph (BRN)

TECHNOLOGICAL FIELDS C1 Bcent C L Q

Electrical engineering. Electronics

observed 6459 0.194 0.345 12.4 0.6simulated 16922 0.068 0.262 5.5

Instruments observed 4542 0.133 0.546 12.3 1.1simulated 12955 0.089 0.216 5.4

Chemicals. Materials observed 9611 0.118 0.319 8.7 1.6simulated 13784 0.038 0.096 4.2

Pharmaceuticals. Biotechnology

observed 5213 0.115 0.390 8.8 1.8simulated 7789 0.063 0.101 4.0

Industrial processes observed 3203 0.166 0.350 9.8 1.4simulated 10232 0.075 0.124 5.0

Mechanical eng. Machines. Transport

observed 1005 0.482 0.441 10.4 1.4simulated 12147 0.081 0.174 5.9

Consumer goods. Civil engineering

observed 201 0.390 0.306 5.3 2.2simulated 5039 0.097 0.147 5.6

W-S model for bipartite graph

Rewiring starts hereRewiring starts

here

Small worlds afterwards?Small worlds:• Scientific instruments• Chemicals & Materials• Pharmaceutical & Biotech • Industrial processes

Not small worlds:• Electronics & Electrical Eng.• Mech. Eng. & Transport• Consumer goods

0 1 2 3 4

01

23

4

Re-scaled distance

Re-

scal

ed c

lust

erin

g

Pharma & Biotech

Chemicals & Materials

Instruments

Elect.Eng. & Electronics

Industrial processes

Consumer Goods

Mech.Eng. & Transport

Random network

Elect.Eng. & ElectronicsScientific InstrumentsChemicals & MaterialsPharma & BiotechIndustrial processesMech.Eng. & TransportConsumer GoodsQ=1

Academic &CNRS inventors as small world catalysts: Centrality

TECHNOLOGICAL FIELDS N BCENT CCENT DCENT

  All inv. 3978 0.0024 0.0837 4.9Electrical engineering. Electronics Uni inv 94 0.0027 0.0811 5.5  CNRS inv 49 0.0037 0.0856 5.5  All inv. 2870 0.0034 0.0841 5.7Instruments Uni inv 147 0.0069 0.0840 6.5  CNRS inv 77 0.0039 0.0844 5.4  All inv. 5723 0.0011 0.1210 7.1Chemicals. Materials Uni inv 268 0.0019 0.1256 8.2  CNRS inv 208 0.0019 0.1257 7.9  All inv. 3608 0.0018 0.1186 6.4Pharmaceuticals. Biotechnology Uni inv 232 0.0034 0.1216 7.0  CNRS inv 183 0.0026 0.1246 7.7  All inv. 2049 0.0035 0.1098 5.6Industrial processes Uni inv 84 0.0081 0.1146 6.8  CNRS inv 68 0.0038 0.1177 6.0

Academic &CNRS inventors as small world catalysts: Node-deletion test

TECHNOLOGICAL FIELD Nr removed C1 ∆C1 L ∆L/L(1) 6459 12.4

Electrical engineering. Electronics (2) 143 6068 391 12.7 2.2%(3) 143 6118 341 12.6 1.7%(1) 4542 12.3

Instruments (2) 224 3452 1090 12.1 -2.0%(3) 224 3971 571 12.6 2.0%(1) 9611 8.7

Chemicals. Materials (2) 476 8538 1073 9.6 9.5%(3) 476 8827 784 9.0 2.6%(1) 5213 8.8

Pharmaceuticals. Biotechnology (2) 415 4247 966 9.5 8.6%(3) 415 4443 770 8.9 1.7%(1) 3203 9.8

Industrial processes (2) 152 2769 434 11.2 14.3%(3) 152 2882 321 9.9 0.8%

Summary Networks of inventors in France are “small

worlds” In science-intensive technological fields Shortcuts due to inter-organizational mobility of

inventors

Academic and CNRS inventors & “small worlds” Connect otherwise disconnected components Bridge between distant communities of inventors

shortening distances