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Prolific inventors and their mobility: scale, impact and

significanceTowards a theoretical

background for “prolificness”Conference

GREDEF Nice 14th June

Christian Le BasEmail : christian.lebas@univ-lyon2.fr

LEFI, Institut des Sciences de l'Homme14, avenue Berthelot69363 LYON CEDEX07

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Contents

1. Literature Survey on prolific inventors2. The Economics of “prolificness”3. The French prolific inventors (preliminary

results)4. Inventor mobility: scale, determinants,

and theoretical background

5. The mobility of French prolific inventors (preliminary results)

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Main references of the research Group• Gay C. (2003), Economie de l’innovation localisée. Thèse

U. Lyon2.• Le Bas C., Latham W., (ed.), (2006), The Economics of

Persistent Innovation: an Evolutionary View, Springer.• Le Bas C. et al., (2007), « Collective Knowledge, Prolific

Inventors and the Value of Inventions: An Empirical Study of French, German and British Owned U.S. Patents », The Economics of Innovation and New Technology in a special issue on Knowledge Governance.

• Le Bas C., (2007), « Mobilité des inventeurs, réseaux sociaux de connaissances et performance de l’activité inventive. Une analyse quantitative sur plusieurs pays », ANR Project, Juin.

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1. Literature Survey on Prolific Inventors1. Basic reference Lotka 1926 observation

- The number of highly productive scientists was a relatively small fraction of all scientists.

2. Narin and Breitzman (1995) : seminal paper on “highly prolific inventor”- Investigation for 4 companies in the area of semiconductors, “inventor name unification” (3000 inventors)- “Every inventor… is given credit for the whole invention regardless the number of co-inventors”- “ … the key role of a few researchers seems to be a law of nature” (p. 519)- “One, two or three individuals are really driving their laboratory….companies should make effort to retain and nurture these key contributors”

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3.The two Trajtenberg studies

a. “The name game…” (May 2004)- Method pour two stages methodology for matching

names of inventor: 1. put together records having the identical inventor name (Christian Le Bas, C. Le Bas…), 2. use the SOUNDEX coding method

- First assessment from the NBER Patent Data File (1975-1999): 2 million patents, 2 inventors per patents on average: 4,298,912 records, after matching with the Trajtenberg procedure: 1,565,780 inventors

- First overview: just one patent: 58%… 10 patents or more: 5%

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3.(suite) The two Trajtenberg studies

b. “Tracing the mobility of inventors…” (Oct. 2004)- Mobility of inventors across assignees: number of

inventors movers 216,591 (but need to consolidate assignee code)

- Inventors across countries: 641,127 one country… 1 only (?) 6 countries

- Flows of inventors Matrix (across countries): more important cells: US/GB, US/CA, US/Jap, US/Ger. For France ranking: USA, Ger, CB, CH, Jap, It , Sw.

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4. Kim et al. (2005)

- Study on patents and inventors with the Trajtenberg method

- Add dissertation abstract to inventor data for mapping and explaining the International Knowledge Flows

- Two industry firm: pharmaceutical and semiconductor

- Results: an increase in the extent that US innovators access researchers with foreign R&D experience

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5. A first measure of the scale of prolific inventors population (Latham et al., 2006)

Number of patents France Germany UK Japan TOTAL

1 56,72 50,24 52,14 42,74 47,32

2-9 38,76 41,83 42,03 45,89 43,59

10-49 4,36 7,41 5,60 10,64 8,53

50 et plus 0,16 0,53 0,23 0,73 0,56

TOTAL 100,00 100,00 100,00 100,00 100,00

Distribution of inventors according to the number of US patents by country, 1975-1999 (%)

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Patents including a prolific inventor by country

US patents (1975-1999)

France Germany UK Japan

Number of patents including a prolific

inventor

26.299 111.985 24.448 368.844

Proportion of patents

including a prolific inventor (%)

40.45 65.93 42.29 94.41

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2. The Economics of prolificness

- Latham et al. (2007) : Patents granted by the US Patent Office to French, German and British inventors over the period from 1975 to 1999. Negative binomial multiple regression models support for hypotheses that both prolific and foreign inventors tend to be parts of larger teams of inventors and that both prolific and foreign inventors tend to produce inventions having more value.

- Main result from the PATVAL survey - PATVAL survey (7000 patents): The characteristics of the inventor, his past number of patents is more important determinant of the private value of invention than the characteristics of organization in which he is employed (Gambardella et al., 2006).

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No choice between quantity and quality: quantity -quality: - Mobility - inventive productivity (Prolificness) - value of invention- Prolific inventors as a “Knowledge integrator”- Prolific inventors increase the rate at which individuals and organizations learn and consequently achieve sustainable competitive advantages.

2. The Economics of prolificness (suite)

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2. The Economics of prolificness (suite)

Prolific inventors: can we learn from the “stars scientists” (Zucker and Darby, 2002) model?“stars scientists” = individuals with higher-quality intellectual capital (measured in terms of number of citations) who are “entrepreneurial individuals” Are PI “entrepreneurial individuals” ?

Prolific inventor as an Entrepreneurial researcher Entrepreneurial researcher who is necessarily an entrepreneur but he (she) is active towards technology transfer and partnership with industry (Sessano, 2006).

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- importance of the tacit character of the new discoveries. Knowledge is embodied in individuals, that implies “bench-level” collaboration which is measured by co-authoringFor PI tacit knowledge is presumably important as well (measured by the scale of the team of inventors?)

- important regional network effects: “ stars have a higher probability of moving to a firm when there are more top-quality universities in their region, a competing influence”

- this should be confirmed/infirmed for PI

2. The Economics of prolificness (suite)

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Aim of the research project: studying one aspect of prolificness:Assessing the effects of pi mobility (across firms and across regions) on the value of patents

Study on 5 countries: USA, Jap.,Ger;, Fr, UK

2. The Economics of prolificness (suite)

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3. The French prolific inventors (preliminary results)

Some data on french (US) patenting (1975-2002):

Number of French inventors: 59090Number of patents: 81176Average number of patents per inventor: 1.37

Number of French pi (> 14 patents): 1215Number of patents: 21807Average number of patents per pi: 17.95

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3. The French prolific inventors (preliminary results)

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4. Inventor mobility: scale, determinants, and theoretical background1.The determinants of inventor mobilityTrajtenberg (2004) regresses (negative binomial function) the number of moves across (per inventor).New variables : - age = 1999 – year of first patent, different from : duration = last year – first year- moves of inventors correlated with - “younger” inventors (sign of age = negative)- Inventors having More patents in Drug and med.- Inventors having More partners (Large R&D team?)- Inventors More techno. Specialised (less techno. Diversified)- Inventors having More important patents (more citations), the reverse in Japan- Inventors US (versus Japanese)

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2. Inventor mobility, inventor performance and value of invention: empirical evidence

- Turner (2003): elasticity quality of publication/ mobility of researchers in Physic (CNRS) = 0,3 citation more with mobility.

- Trajtenberg (2004) main result: correlation between value of invention and inventor mobility

What causality?- Hoisl (2006): mobile inventors are more than four times

as productive (patent per inventor divided by the age of inventor in 2002 minus 25) as non-movers (survey of 3049 German inventors), the level of education has no influence and an increase of productivity decreases the number of moves. This short-term effect seems verified by Trajtenberg as well.

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3. Inventor mobility: theoretical background

- The state of the Art: “The transfer of key individuals may suffice when the knowledge to be transferred related to the particulars of a separable routines… only a limited range of capabilities can be transferred… More often than not, the transfer of productive expertise requires the transfer of organizational as well as individual knowledge”. (Teece, 1982, p. 45).

- Hypothesis: prolific inventor as repository of organizational knowledge?

- Individual mobility as an important source of knowledge externalities (Moen, 2005).

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3. (suite) Inventor mobility: theoretical background

- Personnel rotation as a mechanism of transferring knowledge (Argote, 2006).

- Inventor mobility as a “tour de France” = human capital formation.

- Inventor mobility as a mean for technological diffusion and key mechanism to transfer tacit knowledge between firms (Almeida and Kogut, 1999; Rosenkopf and Almeida, 2003; Stolpe, 2002).

- Learning-by-hiring: study from Song et al. (2003) on the patenting activities of engineers.

- Strategic mobility (Kim , 2005)

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3. (suite) Inventor mobility: theoretical background

- “Knowledge flows are localized to the extent labour mobility also is” (Breschi et Lissoni, 2003). Through the hiring of inventors the firm can get access to the inventor capital of contacts.

- See also Agrawal et al. (2003): social ties falicilitata knowledge transfer that persist even after co-located individuals (inventors) are separated.

- Knowledge “reuse” (Langlois, 2001), increasing economies of scale at the core of economic growth.

- Mobility inter- versus intra-firm: researcher mobility inside R&D network still important (short-term form of mobility less costly and effective inside MNC; Criscuolo, 2005).

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5.The mobility of French prolific inventors (preliminary results)

Table 1 Mobility of prolific inventors across assignees

Number of patents related to prolific inventorsNumber of moves

15-30 31-50 51-100 >100 Total226 41 8 5 280

0 (23,79) (21,24) (14,04) (33,33) (23,05)91 19 4 1141 (9,58) (9,84) (7,02) (0,00) (9,38)128 21 7 4 1602 (13,47) (10,88) (12,28) (26,67) (13,17)90 13 3 1063 (9,47) (6,74) (5,26) (0,00) (8,72)79 13 6 2 1004 (8,32) (6,74) (10,53) (13,33) (8,23)64 11 2 1 785 (6,74) (5,70) (3,51) (6,67) (6,42)52 7 3 1 636 (5,47) (3,63) (5,26) (6,67) (5,19)50 9 1 607 (5,26) (4,66) (1,75) (0,00) (4,94)38 9 5 528 (4,00) (4,66) (8,77) (0,00) (4,28)26 10 2 389 (2,74) (5,18) (3,51) (0,00) (3,13)36 6 2 4410 (3,79) (3,11) (3,51) (0,00) (3,62)70 34 14 2 120+10 (7,37) (17,62) (24,56) (13,33) (9,88)950 193 57 15 1215Total (100,00) (100,00) (100,00) (100,00) (100,00)

Source : Our own calculations

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5.The mobility of French prolific inventors (preliminary results)

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Table 4 Number of years from the first application patent to the last one*Number of patents related to prolific inventors

Number of years15-30 31-50 51-100 >100 Total280 30 5 0 315

0-10(29,47) (15,54) (8,77) (0,00) (25,93)

494 87 18 6 60511-21

(52,00) (45,08) (31,58) (40,00) (49,79)176 76 34 9 295

22-32(18,53) (39,38) (59,65) (60,00) (24,28)

950 193 57 15 1215Total

(100,00) (100,00) (100,00) (100,00) (100,00)Source : Our own calculations

* variable duration for Trajtenberg (2004)

5.The mobility of French prolific inventors (preliminary results)

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Conclusion and research agenda

- Main conclusion: Knowledge (labour) markets more important than Knowledge (non-market) spillovers?

- Prolific inventor as persistent inventor (Latham et al., 2006): U-shape relationship between inventive performance (number of patents per inventor) and duration, but what are the effects of moves in this relationship (dummy for mobility).

- Hypothesis about a taxonomy of prolific inventor (pi): fast pi (being prolific once he begins to invent) persistent pi (becoming prolific through experience and mobility).

- Extension: to what extent the prolificness and the mobility (within or between the firms) of prolific inventor could explain firm R&D performance (see Redor, 2004).