Inventors' small worlds: academic and CNRS researchers in ...

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Dec 6, 2012 (4 years and 6 months ago)

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

F
RANCESCO

L
ISSONI

(
1
)
, P
ATRICK

L
LERENA
(
2
)
, B
ULAT

S
ANDITOV
(
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 FIELDS

Productivity

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 INVENTORS

Patents

Inventors

Small worlds: Watts &
Strogatz

(1998)


“Small world” networks:

o

sparse

o

clustered

o

short distances



WS model of SW:







Small
-
world ratio:

Q=(C
obs
/
С
rg
)
/
(L
obs
/
L
rg
)

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

B
cent

C

L

Q

Electrical engineering.
Electronics

observed

6459

0.194

0.345

12.4

0.6

simulated

16922

0.068

0.262

5.5

Instruments

observed

4542

0.133

0.546

12.3

1.1

simulated

12955

0.089

0.216

5.4

Chemicals. Materials

observed

9611

0.118

0.319

8.7

1.6

simulated

13784

0.038

0.096

4.2

Pharmaceuticals.
Biotechnology

observed

5213

0.115

0.390

8.8

1.8

simulated

7789

0.063

0.101

4.0

Industrial processes

observed

3203

0.166

0.350

9.8

1.4

simulated

10232

0.075

0.124

5.0

Mechanical eng. Machines.
Transport

observed

1005

0.482

0.441

10.4

1.4

simulated

12147

0.081

0.174

5.9

Consumer goods. Civil
engineering

observed

201

0.390

0.306

5.3

2.2

simulated

5039

0.097

0.147

5.6

W
-
S model for bipartite graph

Rewiring starts here

Rewiring 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
0
1
2
3
4
Re-scaled distance
Re-scaled clustering
Pharma & Biotech
Chemicals & Materials
Instruments
Elect.Eng. & Electronics
Industrial processes
Consumer Goods
Mech.Eng. & Transport
Random network
Elect.Eng. & Electronics
Scientific Instruments
Chemicals & Materials
Pharma & Biotech
Industrial processes
Mech.Eng. & Transport
Consumer Goods
Q=1
Academic &CNRS inventors as small
world catalysts: Centrality

TECHNOLOGICAL FIELDS

N

B
CENT

C
CENT

D
CENT



All inv.

3978

0.0024

0.0837

4.9

Electrical 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

5.7

Instruments

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

7.1

Chemicals. 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

6.4

Pharmaceuticals. 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

5.6

Industrial 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

⠱)

㘴㔹

12.4

䕬散tric慬⁥湧 湥敲i湧. 䕬散tr潮o捳

⠲)

ㄴ1

㘰㘸

㌹3

12.7

2.2%

⠳)

ㄴ1

㘱ㄸ

㌴3

12.6

1.7%

⠱)

㐵㐲

12.3

I湳tr畭敮ts

⠲)

㈲2

㌴㔲

㄰㤰

12.1

-
2.0%

⠳)

㈲2

㌹㜱

㔷5

12.6

2.0%

⠱)

㤶ㄱ

8.7

䍨敭楣慬献 䵡t敲i慬s

⠲)

㐷4

㠵㌸

㄰㜳

9.6

9.5%

⠳)

㐷4

㠸㈷

㜸7

9.0

2.6%

⠱)

㔲ㄳ

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