Patterns of Research Collaboration in Patterns of Research Collaboration in U.S. Universities, 1981-1999U.S. Universities, 1981-1999

AAAS MeetingsAAAS MeetingsDenver, ColoradoDenver, ColoradoFebruary 18, 2003February 18, 2003

James D. Adams, University of Florida and NBERJames D. Adams, University of Florida and NBER

Grant C. Black, Georgia State UniversityGrant C. Black, Georgia State University

Roger Clemmons, University of FloridaRoger Clemmons, University of Florida

Paula E. Stephan, Georgia State UniversityPaula E. Stephan, Georgia State University

OverviewOverview

This is a study of collaboration in university This is a study of collaboration in university research over the period 1981-1999.research over the period 1981-1999.

The topic is important for at least two reasons: (1) The topic is important for at least two reasons: (1) collaboration is a means by which knowledge collaboration is a means by which knowledge spills over, and (2) collaboration is linked to the spills over, and (2) collaboration is linked to the division of labor.division of labor.

So one might think that the economic efficiency of So one might think that the economic efficiency of the knowledge-creating industries is related to the knowledge-creating industries is related to collaborative activities.collaborative activities.

OverviewOverview

The study includes 110 leading U.S. universities and all The study includes 110 leading U.S. universities and all major sciences in these universities. major sciences in these universities.

The primary data set includes 2.4 million scientific The primary data set includes 2.4 million scientific papers and 18.8 million citations to these papers.papers and 18.8 million citations to these papers.

Also included is information on field and the number Also included is information on field and the number and location of authors.and location of authors.

12 fields are represented: agriculture, astronomy, 12 fields are represented: agriculture, astronomy, biology, chemistry, computer science, economics, earth biology, chemistry, computer science, economics, earth science, engineering, mathematics, medicine, physics, science, engineering, mathematics, medicine, physics, and psychology.and psychology.

The data source is the Institute for Scientific The data source is the Institute for Scientific Information (ISI).Information (ISI).

Principal Findings on CollaborationPrincipal Findings on Collaboration

Research output of the U.S. university system Research output of the U.S. university system expanded by 50% over the period but grew at a expanded by 50% over the period but grew at a faster rate in the 1980s than in the 1990s.faster rate in the 1980s than in the 1990s.

Research collaboration grew in each of the three Research collaboration grew in each of the three dimensions that we measure.dimensions that we measure.

Authors per paper increased from 2.8 to 4.2 over Authors per paper increased from 2.8 to 4.2 over the period 1981-1999.the period 1981-1999.

Top 110 institutions per paper increased 1.1 to 1.2, Top 110 institutions per paper increased 1.1 to 1.2, while the share of foreign authors increased from while the share of foreign authors increased from 5% to 15% over the same time period.5% to 15% over the same time period.

Exhibits 1-3 illustrate. Exhibits 1-3 illustrate.

Exhibit 1--Number of Scientific PapersIn the Top 110 Universities, 1981-1999

60000

80000

100000

120000

140000

160000

81 84 87 90 93 96 99

Year

Nu

mb

er o

f Pap

ers

Number of Papers

Papers Written in Top 110

Exhibit 2--Mean Authors per Paper inThe Top 110 U.S. Universities, 1981-1999

2.40

2.80

3.20

3.60

4.00

4.40

81 84 87 90 93 96 99

Year

Au

tho

rs P

er P

aper

Exhibit 3--Percentage of Top 110 PapersWritten with Other Countries, 1981-1999

0

2

4

6

8

10

12

81 84 87 90 93 96 99

Year

Perc

enta

ge

Foreign Corporation

Foreign Government

Foreign Medical Center

Foreign School

Other Foreign

Comparative Trends in Main Forms Of Comparative Trends in Main Forms Of Scientific CollaborationScientific Collaboration

Exhibit 4 brings the three dimensions of Exhibit 4 brings the three dimensions of collaboration together, normalizing each collaboration together, normalizing each dimension on its 1981 value. dimension on its 1981 value.

Team size (number of authors) is growing faster Team size (number of authors) is growing faster than U.S. institutional collaboration (number of than U.S. institutional collaboration (number of top 110 schools).top 110 schools).

The share of foreign addresses is rising faster than The share of foreign addresses is rising faster than the other two indicators. These patterns are robust the other two indicators. These patterns are robust across fields of science.across fields of science.

The rise in international collaboration has taken The rise in international collaboration has taken place in the recent past.place in the recent past.

Exhibit 4--Indicators of RelativeTrendIn Scientific Collaboration, 1981-1999

(1981=1.0)

00.5

11.5

22.5

33.5

81 84 87 90 93 96 99

Year

Col

labo

ratio

n In

dex

Top 110 Schools Per Paper

Authors Per Paper

Fraction Foreign

Trends in International Collaboration by Trends in International Collaboration by Size of TeamSize of Team

We now explore cross-sectional patterns in the We now explore cross-sectional patterns in the trends of the internationalization of science.trends of the internationalization of science.

As the measure of internationalization we again As the measure of internationalization we again use the foreign share of addresses on scientific use the foreign share of addresses on scientific papers.papers.

We normalize on the 1981 value in order to We normalize on the 1981 value in order to compare growth patterns.compare growth patterns.

Exhibit 5 shows that smaller teams, while less Exhibit 5 shows that smaller teams, while less international, are becoming more international at a international, are becoming more international at a faster rate.faster rate.

Exhibit 5--Growth in the Foreign Share of U.S. Papers,1981-1999, by Size of Team (1981=1.0)

0

0.5

1

1.5

2

2.5

3

81 84 87 90 93 96 99

Year

Team

Siz

e (1

981=

1.0)

Foreign Share,1-4 Authors

Foreign Share,5-8 Authors

Foreign Share,9-12 Authors

Foreign Share,13+ Authors

Trends in International CollaborationTrends in International CollaborationBy FieldBy Field

Exhibits 6 and 7 compare the growth of Exhibits 6 and 7 compare the growth of internationalization by field.internationalization by field.

The most international fields are astronomy, The most international fields are astronomy, mathematics, and physics. The least international mathematics, and physics. The least international are agriculture, biology, and medicine. Exhibit 6 are agriculture, biology, and medicine. Exhibit 6 points out the differences in natural units.points out the differences in natural units.

Exhibit 7 normalizes the fields on 1981 values. Exhibit 7 normalizes the fields on 1981 values. This shows that the least international fields are This shows that the least international fields are becoming more international at a faster rate.becoming more international at a faster rate.

Exhibit 6--Trends in Internationalization of U.S. Science,1981-1999

0

0.05

0.1

0.15

0.2

0.25

81 84 87 90 93 96 99

Year

Fra

ctio

n F

ore

ign Most international:

Astronomy,Mathematics, andPhysics

Least international:Agriculture, Biology,and Medicine

Exhibit 7--Trends in Internationalization of U.S. Science, 1981-1999 (1981=1.0)

00.5

11.5

22.5

33.5

4

1981 1984 1987 1990 1993 1996 1999

Year

Frac

tion

Fore

ign

Most International:Astronomy,Mathematics, andPhysics

Least International:Agriculture, Biology,and Medicine

ConclusionsConclusions

Over time, scientific research has invited the use Over time, scientific research has invited the use of larger teams.of larger teams.

In recent years research teams have become In recent years research teams have become increasingly internationalized.increasingly internationalized.

There is convergence in the size distribution: team There is convergence in the size distribution: team sizes that are the least international are becoming sizes that are the least international are becoming international at a faster rate.international at a faster rate.

There is convergence across scientific fields: the There is convergence across scientific fields: the least international of fields are becoming more least international of fields are becoming more international at a faster rate.international at a faster rate.

ConclusionsConclusions

Why is this happening?Why is this happening? Is it because of an increasing range of Is it because of an increasing range of

complementary skills and equipment needed to do complementary skills and equipment needed to do the research, coupled with rising specialization?the research, coupled with rising specialization?

Or is it due to a decline of the cost of research Or is it due to a decline of the cost of research conducted at a distance?conducted at a distance?

Or to the rise of scientific research outside the Or to the rise of scientific research outside the U.S.?U.S.?

Probably it is the last two explanations that are the Probably it is the last two explanations that are the most compelling, given the speed of the change most compelling, given the speed of the change that we observe.that we observe.