Knowledge flows in global renewable energy innovation systems: the role of technological and geographical distance

Figures & data

Table 1. Mean, standard deviation and correlation of variables.

	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)	(11)
1. Technological impact	1.000	0.332	0.166	0.307	0.096	0.171	0.151	0.034	−0.046	0.158	0.034
2. Domestic_Proximate	0.332	1.000	0.464	0.347	0.113	0.548	0.058	0.000	−0.089	0.252	0.099
3. Domestic_Distant	0.166	0.464	1.000	0.034	0.449	0.554	0.114	0.041	−0.067	0.359	0.128
4. International_Proximate	0.307	0.347	0.034	1.000	0.186	0.029	0.173	0.018	−0.040	0.174	0.097
5. International_Distant	0.096	0.113	0.449	0.186	1.000	0.061	0.281	0.070	−0.041	0.348	0.140
6. Absorptive capacity	0.171	0.548	0.554	0.029	0.061	1.000	−0.066	0.008	−0.067	0.178	0.079
7. Family size	0.151	0.058	0.114	0.173	0.281	−0.066	1.000	0.053	−0.053	0.267	0.008
8. Team size	0.034	0.000	0.041	0.018	0.070	0.008	0.053	1.000	0.126	0.177	−0.083
9. Public	−0.046	−0.089	−0.067	−0.040	−0.041	−0.067	−0.053	0.126	1.000	0.157	−0.052
10. Non-patent literature	0.158	0.252	0.359	0.174	0.348	0.178	0.267	0.177	0.157	1.000	−0.016
11. Citation lag	0.034	0.099	0.128	0.097	0.140	0.079	0.008	−0.083	−0.052	−0.016	1.000
Mean	4.009	0.589	0.712	0.955	1.136	2.321	4.697	2.679	0.141	0.889	7.06
SD	6.73	0.818	0.974	0.881	0.985	2.262	4.202	1.814	0.348	1.101	4.094
Min	0	1.1	1.1	1.609	1.792	0	1	1	0	0	0
Max	141	4	6	5.694	6.8	8.526	132	28	1	7	30

Table 2. Econometric results.

Model	(1)	(2)
	Negative binomial model
Dependent variable	Number of forward citations (five-year citation window)
Time period	1990–2010	1990–2010
Domestic_Proximate	0.257***	0.318***
	(0.011)	(0.020)
Domestic_Distant	−0.073***	−0.106***
	(0.011)	(0.020)
International_Proximate	0.392***	0.538***
	(0.010)	(0.013)
International_Distant	−0.053***	−0.008
	(0.009)	(0.012)
Domestic_Proximate*Absorptive_Capacity		0.0002
		(0.005)
Domestic_Distant*Absorptive_Capacity		0.017***
		(0.005)
International_Proximate*Absorptive_Capacity		−0.063***
		(0.004)
International_Distant*Absorptiv_Capacity		−0.020***
		(0.004)
Absorptiv_Capacity	0.015*	0.079***
	(0.008)	(0.010)
Family size	0.033***	0.032***
	(0.002)	(0.002)
Team size	0.034***	0.034***
	(0.004)	(0.004)
Public	−0.130***	−0.135***
	(0.022)	(0.022)
Non-patent literature	0.052***	0.053***
	(0.008)	(0.008)
Citation lag	−0.007***	−0.008***
	(0.002)	(0.002)
Constant	−0.986***	−1.137***
	(0.132)	(0.132)
Country dummy	Yes	Yes
Technology dummy	Yes	Yes
Time dummy	Yes	Yes
Observations	30,720	30,720
Log likelihood	−69,362.900	−69,186.320

Note: *Significant at 0.1, **significant at 0.05 and ***significant at 0.01

Figure 1. Interaction plots.

Table 3. Robustness check.

Model	(1)	(2)	(3)
	Negative binomial	Negative binomial	Logit
Dependent variable	10-year citation window	5-year citation window Patent with at least one backward citation	5-year citation window Highly-cited
Time period	1990–2005	1990–2010	1990–2010
Domestic_Proximate	0.281***	0.309***	0.463***
	(0.046)	(0.020)	(0.077)
Domestic_Distant	−0.133***	−0.115***	−0.226***
	(0.039)	(0.020)	(0.082)
Intentational_Proximate	0.617***	0.529***	0.826***
	(0.027)	(0.013)	(0.062)
International_Distant	−0.020	−0.015	0.021
	(0.024)	(0.012)	(0.058)
Domestic_Proximate*Absorptive_Capacity	0.061***	0.001	0.014
	(0.017)	(0.005)	(0.016)
Domestic_Distant*Absorptive_Capacity	0.001	0.018***	0.033*
	(0.015)	(0.005)	(0.018)
Intentational_Proximate*Absorptive_Capacity	−0.092***	−0.061***	−0.085***
	(0.013)	(0.004)	(0.015)
International_Distant*Absorptive_Capacity	−0.038***	−0.019***	−0.025*
	(0.012)	(0.004)	(0.015)
Absorptive_Capacity	0.058**	0.074***	0.089**
	(0.027)	(0.010)	(0.041)
Family size	0.033***	0.031***	0.050***
	(0.003)	(0.002)	(0.005)
Team size	0.030***	0.033***	0.084***
	(0.007)	(0.004)	(0.015)
Public	−0.130***	−0.136***	−0.167*
	(0.037)	(0.022)	(0.095)
Non-patent literature	0.102***	0.054***	0.087***
	(0.014)	(0.008)	(0.027)
Citation lag	−0.007**	−0.011***	−0.029***
	(0.003)	(0.002)	(0.009)
Constant	−0.318*	−1.056***	−4.827***
	(0.166)	(0.136)	(0.539)
Country dummy	Yes	Yes	Yes
Technology dummy	Yes	Yes	Yes
Time dummy	Yes	Yes	Yes
Observations	9,203	29,383	30,720
Log likelihood	−27,696.630	−67,110.490	−4,875.862

Note: *Significant at 0.1, **significant at 0.05 and ***significant at 0.01