**4. Results**

In order to analyze the evolution of collaboration across distance, we obtain the mean and standard deviation of each proximity dimension in the period 2001–2005 and 2006–2010 for Spain, Greece, Italy, and Portugal. **Table 2** displays the results including data for all disciplines. **Tables 3–5** show the descriptives for *Chemistry* & *Chemical*, *Life Sciences* and *Physics* & *Astronomy*, respectively.

The following conclusions are drawn from the results of **Table 2**:


**All Countries**

**01–05** **Geographical distance**

Geodistij

8.6937

9.5126

9.42

10.4664

11.2584

7.57

14.2690

15.2108

6.59

9.8263

10.7625

9.53

11.0458

11.3480

2.74

(7.34)

**Cognitive distance**

Cogndistij

0.7817

0.7868

0.65

0.7834

0.7869

0.45

0.7970

0.8034

0.80

0.7769

0.7819

0.64

0.7898

0.7962

0.81

(0.05)

**Institutional distance**

Regionij

0.0621

0.0526

−15.30

0.0430

0.0322

−25.12

0.0638

0.0581

−8.93

0.0353

0.0289

−18.13

0.0760

0.0569

−25.13

(0.24)

Countryij

0.6173

0.5510

−10.70

0.4313

0.3645

−15.49

0.3161

0.2940

−6.99

0.5330

0.4642

−12.91

0.2496

0.2267

−9.17

(0.49)

**Social proximity**

Socialproxij

—

0.6848

—

—

0.6554

—

—

0.4513

—

—

0.6876

—

—

0.5248

—

(0.50)

Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European…

(0.46)

(0.50)

(0.48)

(0.46)

**Organizational proximity**

Educproxij

5.7874

5.6786

−1.88

6.1203

6.0237

4.64

3.8997

3.7790

−3.10

5.7466

5.6445

−1.78

6.3322

6.2153

−1.85

(1.80)

Staffdistij

1939.01

1878.22

−3.14

2037.58

1947.88

−1.58

1767.02

1744.74

−1.26

2024.37

1985.35

−1.93

1620.53

1644.70

1.49

(1676.61)

**Economic distance**

GDPdistij

0.0062

0.0063

1.61

0.0060

0.0061

1.67

0.0063

0.0059

−6.35

0.0066

0.0068

3.03

0.0066

0.0067

1.52

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

35

(1631.56)

(1717.26)

(1650.28)

(1621.03)

(1579.96)

(1734.05)

(1692.64)

(1399.37)

(1414.75)

http://dx.doi.org/10.5772/intechopen.77370

(1.82)

(1.57)

(1.61)

(2.16)

(2.04)

(1.80)

(1.82)

(1.30)

(1.41)

(0.50)

(0.50)

(0.48)

(0.47)

(0.46)

(0.50)

(0.50)

(0.43)

(0.42)

(0.22)

(0.20)

(0.18)

(0.24)

(0.23)

(0.18)

(0.17)

(0.27)

(0.23)

(0.05)

(0.04)

(0.04)

(0.05)

(0.06)

(0.05)

(0.05)

(0.04)

(0.04)

(7.84)

(7.21)

(7.59)

(10.81)

(11.14)

(7.16)

(7.36)

(9.55)

(9.50)

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**ES**

**GR**

**IT**

**PT**


of collaborating pairs has increased from 3669 to 4775 and total collaboration has substantially increased by 51.38%. From all possible pairs of universities, 24.10% has collaboration in 2001–2005, while it increases to 31.36% in 2006–2010. The intensity of collaboration (number

In order to analyze the evolution of collaboration across distance, we obtain the mean and standard deviation of each proximity dimension in the period 2001–2005 and 2006–2010 for Spain, Greece, Italy, and Portugal. **Table 2** displays the results including data for all disciplines. **Tables 3–5** show the descriptives for *Chemistry* & *Chemical*, *Life Sciences* and *Physics* & *Astronomy*, respectively.

• The average geographical distance among partners has increased over time by 9.42%. This result holds for the four countries in our sample, with an increase ranging from 2.74% in Portugal to 9.53% in Italy. Therefore, we can identify a strong pattern of increasing collabo-

• The mean cognitive distance has slightly increased (0.65% on average for peripheral countries), suggesting a trend toward collaboration with universities specialized in different

• The coefficients of *region and country* strongly decrease over the period of analysis (by 15.30 and 10.74%, respectively), suggesting that institutional proximity decays over time. Thus, there is a trend toward interregional and international collaboration. Focusing on detailed country data, Spain shows the strongest decrease in intra-regional collaboration and intra-national collaboration (25.12–15.49%, respectively). It is also remarkable that Portugal, despite showing a similar decrease in intra-regional collaboration, displays a smaller decrease in intra-national collaboration, and suggesting differences in international openness across these countries.

• The coefficients of variables capturing similarities in educational profile and differences in size decrease in the period 2006–2010 by 1.88–3.14%, respectively. Based on these results, we cannot distinguish a clear trend in organizational distance. Country data shows that similarities in educational profile decrease in Greece, Italy, and Portugal but increase in

• The co-efficient of *GDPdist* remains almost steady for peripheral countries as a whole, while differences in R&D slightly decrease over time. However, there are differences by countries: *GDPdist* increases in all countries but in Greece, where it decreases by 6.35%; and *R&Ddist* increases in Spain, Greece, and Portugal, but decreases in Italy. When focusing in collaboration among convergence regions, it arises that universities tend to collaborate more over time with other universities also located in convergence regions, suggesting that economic distance is increasing its importance as a barrier to SC. Italy is the country, where collaboration among convergence regions experienced the strongest increase (by 5.41%).

Spain. Differences in size decrease in all countries, with the exception of Portugal.

of average collaborations among pairs) has increased from 16.50 to 19.19.

The following conclusions are drawn from the results of **Table 2**:

ration among universities throughout longer geographical distance.

**4. Results**

34 Scientometrics

fields of research.

#### Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European… http://dx.doi.org/10.5772/intechopen.77370 35


**Table 2.** Change in average distance of collaborations per country. About 12 disciplines (Mean and standard deviation).

**All Countries**

**01–05** **Geographical distance**

Geodistij

6.8711

7.9993

16.42

8.9700

9.7482

8.68

13.0388

15.2434

16.91

7.5760

8.9951

18.73

8.3953

9.8989

17.91

(6.30)

**Cognitive distance**

Cogndistij

0.0924

0.0988

0.07

0.1133

0.1166

2.91

0.0821

0.0847

3.17

0.0833

0.0894

7.32

0.0926

0.0991

7.02

(0.08)

**Institutional distance**

Regionij

0.0879

0.0694

−21.05

0.0808

0.0557

−31.06

0.0575

0.0513

−10.78

0.0549

0.0413

−24.77

0.1009

0.0710

−26.63

(0.28)

Countryij

0.7357

0.6465

−12.12

0.5271

0.4517

−14.30

0.4138

0.3282

−20.69

0.6874

0.5810

−15.48

0.3571

0.2759

−22.74

(0.44)

**Social proximity**

Socialproxij

—

0.6439

—

—

0.5842

—

—

0.4462

—

—

0.6723

—

—

0.4828

—

(0.50)

Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European…

(0.47)

(0.50)

(0.49)

(0.48)

**Organizational proximity**

Educproxij

6.1203

5.9715

−2.43

6.4282

6.2213

−3.22

4.2184

3.8615

−8.46

6.0781

5.9531

−2.06

6.4664

6.3732

−1.44

(1.61)

Staffdistij

1973.42

1933.14

−2.04

1998.80

1981.83

−0.85

1883.60

1822.17

−3.26

2033.37

2012.00

−1.05

1531.05

1569.63

2.52

(1661.11)

**Economic distance**

GDPdistij

0.0059

0.0061

3.39

0.0056

0.0058

3.57

0.0059

0.0057

−3.39

0.0062

0.0065

4.84

0.0064

0.0065

1.56

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

37

(1646.25)

(1622.16)

(1625.04)

(1767.60)

(1675.70)

(1723.08)

(1721.78)

(1199.39)

(1318.44)

http://dx.doi.org/10.5772/intechopen.77370

(1.69)

1.32

(1.51)

(2.21)

(2.16)

(1.64)

(1.70)

(1.09)

(1.21)

(0.48)

(0.50)

(0.50)

(0.50)

(0.47)

(0.46)

(0.50)

(0.48)

(0.45)

(0.25)

(0.27)

(0.23)

(0.23)

(0.22)

(0.23)

(0.20)

(0.30)

(0.26)

(0.08)

(0.09)

(0.09)

(0.07)

(0.07)

(0.07)

(0.07)

(0.07)

(0.07)

(7.04)

(6.80)

(7.06)

(11.23)

(11.54)

(6.30)

(6.85)

(8.27)

(8.78)

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**ES**

**GR**

**IT**

**PT**


**All Countries**

**01–05**

> R&Ddistij

0.1092

0.1086

−0.55

0.0957

0.0969

1.25

0.1064

0.1091

2.54

0.1340

0.1336

−0.30

0.0854

0.0855

0.12

(0.09)

Convergenceij

(0.05)

N°. Obs.

**Table 2.**

Change in average distance of collaborations per country. About 12 disciplines (Mean and standard deviation).

3669

4775 Source: ISI Web of Science, EUMIDA and Eurostat. Own elaboration.

30.14

1929

2612

35.41

329

534

62.31 2210

2807

27.01

605

966

59.67

(0.49)

(0.49)

(0.49)

(0.50)

(0.50)

(0.49)

(0.49)

(0.50)

(0.50)

0.4044

0.4241

4.87

0.4126

0.4227

2.45

0.4800

0.4972

3.58

0.3792

0.3997

5.41

0.5091

0.5316

4.42

(0.09)

(0.07)

(0.07)

(0.09)

(0.09)

(0.09)

(0.09)

(0.07)

(0.08)

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

36 Scientometrics

**ES**

**GR**

**IT**

**PT**

#### Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European… http://dx.doi.org/10.5772/intechopen.77370 37


**Table 3.** Change in average distance of collaborations per country. Chemistry and chemical (Mean and standard deviation).

**All Countries**

**01–05**

**Geographical distance**

Geodistij

7.1094

7.5915

6.78

9.1112

9.4409

3.62

13.8785

13.7744

−0.75

7.5194

8.2657

9.92

10.5613

9.9425

−5.86

(6.78)

**Cognitive distance**

Cogndistij

0.0826

0.0905

9.56

0.0856

0.0924

7.94

0.1051

0.1079

2.66

0.0716

0.0788

10.06

0.1357

0.1285

−5.31

(0.08)

**Institutional distance**

Regionij

0.0817

0.0705

−13.71

0.0796

0.0585

−26.51

0.0769

0.0643

−16.38

0.0500

0.0448

−10.40

0.0803

0.0628

−21.79

(0.27)

Countryij

0.7427

0.6786

−8.63

0.5361

0.4712

−12.11

0.3846

0.3684

−4.21

0.7116

0.6441

−9.49

0.3092

0.2601

−15.88

(0.44)

**Social proximity**

Socialproxij

—

0.5828

—

—

0.4901

—

—

0.3275

—

—

0.6159

—

—

0.4081

—

(0.50)

Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European…

(0.49)

(0.47)

(0.50)

(0.49)

**Organizational proximity**

Educproxij

6.2551

6.1164

−2.22

6.5286

6.4119

−1.79

4.2596

4.1813

−1.84

6.2348

6.0814

−2.46

6.6426

6.5381

−1.57

(1.43)

Staffdistij

2023.76

1913.63

−5.44

2067.18

1964.94

−4.95

1708.24

1679.84

−1.66

2106.67

2008.19

−4.67

1673.21

1573.48

−5.96

(1712.73)

**Economic distance**

GDPdistij

0.0059

0.0060

1.69

0.0057

0.0059

3.51

0.0059

0.0058

−1.69

0.0065

0.0065

0

0.0063

0.0064

1.59

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

39

(1634.33)

(1686.91)

(1635.40)

(1572.05)

(1585.78)

(1781.08)

(1696.95)

(1451.14)

(1325.04)

http://dx.doi.org/10.5772/intechopen.77370

(1.53)

(1.27)

(1.30)

(2.16)

(2.07)

(1.32)

(1.50)

(0.95)

(1.07)

(0.47)

(0.50)

(0.50)

(0.49)

(0.48)

(0.45)

(0.48)

(0.46)

(0.44)

(0.26)

(0.27)

(0.23)

(0.27)

(0.25)

(0.21)

(0.21)

(0.27)

(0.24)

(0.09)

(0.07)

(0.08)

(0.10)

(0.10)

(0.08)

(0.08)

(0.11)

(0.10)

(6.87)

(6.88)

(7.04)

(11.86)

(11.30)

(6.65)

(6.68)

(10.31)

(8.88)

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**ES**

**GR**

**IT**

**PT**


**All Countries**

**01–05**

> R&Ddistij

0.1081

0.1079

−0.19

0.0921

0.0945

2.61

0.1030

0.0999

−3.01

0.1367

0.1373

0.44

0.0738

0.0768

4.07

(0.09)

Convergenceij

(0.48)

N°. Obs.

**Table 3.**

Change in average distance of collaborations per country. Chemistry and chemical (Mean and standard deviation).

1763

2738 Source: ISI Web of Science, EUMIDA and Eurostat. Own elaboration.

55.30

829

1419

71.17 87

195

124.14 1075

1599

48.74

238

493

107.14

(0.049)

(0.49)

0.49

(0.50)

(0.50)

(0.48)

(0.48)

(0.50)

(0.50)

0.3776

0.4004

6.04

0.3945

0.4094

3.78

0.4353

0.4740

8.89

0.3498

0.3734

6.75

0.5210

0.4970

−4.61

(0.09)

(0.08)

(0.08)

(0.08)

(0.08)

(0.09)

(0.09)

(0.07)

(0.07)

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

38 Scientometrics

**ES**

**GR**

**IT**

**PT**

#### Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European… http://dx.doi.org/10.5772/intechopen.77370 39


**Table 4.** Change in average distance of collaborations per country. Life sciences (Mean and standard deviation).

**All Countries**

**01–05** **Geographical distance**

Geodistij

7.3162

8.0470

9.99

9.5294

10.2536

7.60

14.1949

15.3879

8.40

8.0791

8.9452

10.72

9.4753

9.8693

4.16

(6.49)

**Cognitive distance**

Cogndistij

0.1065

0.1047

−1.69

0.0888

0.0877

−1.24

0.0860

0.0938

9.07

0.1193

0.1178

−1.26

0.0745

0.0732

−1.74

(0.93)

**Institutional distance**

Regionij

0.0875

0.0820

−6.29

0.0769

0.0651

−15.34

0.0729

0.0571

−21.67

0.0495

0.0480

−3.03

0.1256

0.1022

−18.63

(0.28)

Countryij

0.7035

0.6534

−7.12

0.4842

0.4433

−8.45

0.2813

0.3029

7.68

0.6430

0.5886

−8.46

0.3478

0.2972

−14.55

(0.46)

**Social proximity**

Socialproxij

—

0.6168

—

—

0.5409

—

—

0.3543

—

—

0.6554

—

—

0.4149

—

(0.49)

Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European…

(0.48)

(0.48)

(0.50)

(0.48)

**Organizational proximity**

Educproxij

5.8197

5.7896

−0.52

6.0315

6.0474

0.26

4.1770

4.2229

1.10

5.7806

5.7815

0.02

6.2512

6.1920

−0.85

(1.83)

Staffdistij

2042.42

2007.24

−1.72

2107.02

2075.72

−1.49

1856.37

1772.30

−4.53

2126.58

2074.59

−2.44

1529.81

1584.70

3.59

(1683.19)

**Economic distance**

GDPdistij

0.0059

0.0061

3.39

0.0058

0.0059

1.72

0.0062

0.0063

1.61

0.0063

0.0065

3.17

0.0062

0.0067

8.06

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.00)

(0.01)

41

(1665.54)

(1663.22)

(1643.10)

(1682.12)

(1572.16)

(1763.80)

(1725.96)

(1139.38)

(1387.78)

http://dx.doi.org/10.5772/intechopen.77370

(1.82)

(1.65)

(1.61)

(2.05)

(2.02)

(1.90)

(1.88)

(1.28)

(1.33)

(0.48)

(0.50)

(0.50)

(0.45)

(0.46)

(0.48)

(0.49)

(0.48)

(0.46)

(0.27)

(0.27)

(0.25)

(0.26)

(0.23)

(0.22)

(0.21)

(0.33)

(0.30)

(0.09)

(0.07)

(0.07)

(0.07)

(0.07)

(0.11)

(0.10)

(0.06)

(0.06)

(7.28)

(6.90)

(7.61)

(10.52)

(11.25)

(6.36)

(7.01)

(8.74)

(9.02)

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**ES**

**GR**

**IT**

**PT**


**All Countries**

**01–05**

> R&Ddistij

0.1076

0.1066

−0.93

0.0882

0.0896

1.59

0.1026

0.1047

2.05

0.1341

0.1360

1.42

0.0864

0.0821

−4.98

(0.09)

Convergenceij

0.3773

0.3991

5.78

0.3881

0.4226

8.89

0.5146

0.5146

0

0.3616

0.3703

2.41

0.5100

0.5269

3.31

(0.48)

N°. Obs.

**Table 4.**

Change in average distance of collaborations per country. Life sciences (Mean and standard deviation).

1811

2483 Source: ISI Web of Science, EUMIDA and Eurostat. Own elaboration.

37.11

804

1242

54.48

104

171

64.42

1120

1450

29.46

249

446

79.12

(0.49)

(0.49)

(0.49)

(0.50)

(0.50)

(0.48)

(0.48)

(0.50)

(0.50)

(0.09)

(0.07)

(0.07)

(0.09)

(0.09)

(0.09)

(0.10)

(0.08)

(0.07)

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

40 Scientometrics

**ES**

**GR**

**IT**

**PT**

#### Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European… http://dx.doi.org/10.5772/intechopen.77370 41


**Table 5.** Change in average distance of collaborations per country. Physics & astronomy (Mean and standard deviation). Next, we check if these results hold for *Chemistry & Chemical*, *Life Sciences* and *Physics &* 

cal distance in *Chemistry & Chemical* increases, with a growth rate ranging from 8.68% in Spain to 18.73% in Italy. Specialization distance also rises, from 2.91% in Spain to 7.32% in Italy. Institutional proximity, that is, collaboration among universities located in the same region/nation decreases over time in peripheral countries. Organizational distance, as mea

sured by differences in staff decreases over time, with the exception of Portugal (where it increases by 2.52%). However, it also comes that there is a trend toward collaboration between universities with different educational profiles, suggesting that organizational distance is increasing throughout the period of analysis. Generally, economic distance in terms of the difference in GDP and R&D expenditures among partners for each country also increases along time, excepting in Greece where it decreases. Our results also show a trend toward collaboration among convergence regions (average growth of 6.04%), except

**Table 4** displays the evolution of distance dimensions for *Life Sciences*. Geographical dis

tance shows contradictory results by countries, with an increase in average collaboration distance in Spain (3.62%) and Italy (9.92%), but a decrease in average distance in Greece and Portugal (0.75 and 5.86%, respectively), specialization distance also increases in Spain (7.94%), Greece (2.66%) and Italy (10.06%). Again, Portugal shows a decrease in average distance (5.31%). Variables capturing institutional proximity show that there is a decrease in intra-regional collaboration and national collaboration, in favor to interregional and international collaboration. In contrast, organizational distance is decreasing over time, with an average decrease of 2.22% in education proximity, 5.44% differences in size. This is universities tend to collaborate more over time with other universities with similar institutional characteristics. Economic distance yields different results for each indicator. GDP distance increases in collaboration pairs in Spain and Portugal but a decrease in Greece. Focusing on R&D distance, there is an increase in Spain (1.59%), Greece (2.05%), and Italy (1.42%) and a decrease in Portugal (4.98%). There is also a trend toward collabo

ration between convergence regions in Spain, Italy, and Portugal, while Greece remains

**Table 5** shows that geographical distance in collaboration in *Physics & Astronomy* increases in peripheral countries, ranging from an increase of 4.16% in Portugal to 10.72% in Italy. Specialization distance decreases by 1.69% in peripheral countries, being Greece an exception (with an increase of 9.07%). Generally speaking, institutional proximity strongly decreases over time, with an increasing share of international and interregional collaboration. The results show that universities tend to collaborate more and more with other universities with similar educational profiles, with the exception of Portugal where it slightly decreases by 0.85%. Distance in size decreases by 1.72% in the whole sample, with the exception of Portugal, where it increases by 3.59%. Economic distance in GDP also increases along time, from 1.61% in Greece to 8.06% in Portugal. Distance in R&D shows different growth rates across countries. It increases in Spain and Greece and decreases in Italy and Portugal. Our results also show a strong trend (7.64%) toward collaboration among convergence regions in

**–**

Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European…

**5**). As shown by **Table 3**, geographi

http://dx.doi.org/10.5772/intechopen.77370


43




*Astronomy* when analyzed separately (**Tables 3**

in Portugal.

equal.

all peripheral countries.

Next, we check if these results hold for *Chemistry & Chemical*, *Life Sciences* and *Physics & Astronomy* when analyzed separately (**Tables 3–5**). As shown by **Table 3**, geographical distance in *Chemistry & Chemical* increases, with a growth rate ranging from 8.68% in Spain to 18.73% in Italy. Specialization distance also rises, from 2.91% in Spain to 7.32% in Italy. Institutional proximity, that is, collaboration among universities located in the same region/nation decreases over time in peripheral countries. Organizational distance, as measured by differences in staff decreases over time, with the exception of Portugal (where it increases by 2.52%). However, it also comes that there is a trend toward collaboration between universities with different educational profiles, suggesting that organizational distance is increasing throughout the period of analysis. Generally, economic distance in terms of the difference in GDP and R&D expenditures among partners for each country also increases along time, excepting in Greece where it decreases. Our results also show a trend toward collaboration among convergence regions (average growth of 6.04%), except in Portugal.

**Table 4** displays the evolution of distance dimensions for *Life Sciences*. Geographical distance shows contradictory results by countries, with an increase in average collaboration distance in Spain (3.62%) and Italy (9.92%), but a decrease in average distance in Greece and Portugal (0.75 and 5.86%, respectively), specialization distance also increases in Spain (7.94%), Greece (2.66%) and Italy (10.06%). Again, Portugal shows a decrease in average distance (5.31%). Variables capturing institutional proximity show that there is a decrease in intra-regional collaboration and national collaboration, in favor to interregional and international collaboration. In contrast, organizational distance is decreasing over time, with an average decrease of 2.22% in education proximity, 5.44% differences in size. This is universities tend to collaborate more over time with other universities with similar institutional characteristics. Economic distance yields different results for each indicator. GDP distance increases in collaboration pairs in Spain and Portugal but a decrease in Greece. Focusing on R&D distance, there is an increase in Spain (1.59%), Greece (2.05%), and Italy (1.42%) and a decrease in Portugal (4.98%). There is also a trend toward collaboration between convergence regions in Spain, Italy, and Portugal, while Greece remains equal.

**Table 5** shows that geographical distance in collaboration in *Physics & Astronomy* increases in peripheral countries, ranging from an increase of 4.16% in Portugal to 10.72% in Italy. Specialization distance decreases by 1.69% in peripheral countries, being Greece an exception (with an increase of 9.07%). Generally speaking, institutional proximity strongly decreases over time, with an increasing share of international and interregional collaboration. The results show that universities tend to collaborate more and more with other universities with similar educational profiles, with the exception of Portugal where it slightly decreases by 0.85%. Distance in size decreases by 1.72% in the whole sample, with the exception of Portugal, where it increases by 3.59%. Economic distance in GDP also increases along time, from 1.61% in Greece to 8.06% in Portugal. Distance in R&D shows different growth rates across countries. It increases in Spain and Greece and decreases in Italy and Portugal. Our results also show a strong trend (7.64%) toward collaboration among convergence regions in all peripheral countries.

**All Countries**

**01–05**

> R&Ddistij

0.1095

0.1066

−2.65

0.0931

0.0939

0.86

0.0962

0.1076

11.85

0.1350

0.1312

−2.81

0.0786

0.0724

−7.89

(0.09)

Convergenceij

(0.48)

N°. Obs.

**Table 5.**

Change in average distance of collaborations per country. Physics & astronomy (Mean and standard deviation).

1703

2158 Source: ISI Web of Science, EUMIDA and Eurostat. Own elaboration.

26.72 793

1076

35.69

96

175

82.29

1112

1332

19.78 207

323

56.03

(0.48)

(0.48)

(0.48)

(0.50)

(0.50)

(0.47)

(0.48)

(0.50)

(0.50)

0.3469

0.3734

7.64

0.3506

0.3727

6.30

0.4681

0.5202

11.13

0.3282

0.3468

5.67

0.4493

0.5046

12.31

(0.09)

(0.08)

(0.08)

(0.7)

(0.09)

(0.10)

(0.09)

(0.07)

(0.07)

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

**01–05**

**06–10**

**%**

42 Scientometrics

**ES**

**GR**

**IT**

**PT**
