Executive alumni networks: Catalysts or constraints for innovation in China’s listed firms?

Figure 1.

Figure 2.

Figure 3.

Baseline Regression_

Variable	Innovation
	(1)	(2)	(3)	(4)
Deg	-13.123*** (-15.29)	-24.978*** (-11.69)	-22.535*** (-10.52)	-11.426*** (-3.80)
Deg2		217.841*** (6.05)	204.783*** (5.64)	137.178*** (3.20)
Cashflow			0.885*** (3.98)	0.216 (1.06)
TobinQ			-0.146*** (-3.14)	-0.124** (-2.53)
ProfitRate			-0.017 (-1.17)	-0.057*** (-4.37)
LiquidityRatio			-0.397*** (-9.10)	-.107*** (-2.66)
ROA			-1.694*** (-4.05)	-0.56 (-1.46)
TTM			0.262 (0.99)	0.094 (0.39)
Age			2.107*** (11.48)	0.5*** (2.93)
Edu			0.736** (7.93)	0.184** (2.17)
Board			0.774** (2.56)	0.291 (1.07)
Constant	2.808*** (125.82)	2.912*** (103.49)	-6.938*** (-8.06)	-0.631 (-0.79)
Industry / Region / Year	No	No	No	Yes
N	10129	10129	10129	10129
Adj.R2	0.033	0.039	0.095	0.271

Other robustness test results_

Variable	(1)	(2)	(3)	(4)
	Manufacturing industry	State enterprise	non-state enterprise	Explanatory variables lagged
Deg	-15.548*** (-4.47)	-10.038** (4.803)	-10.396** (3.951)	-7.499** (-2.53)
Deg2	189.524*** (3.83)	125.289* (68.518)	124.245** (56.525)	109.073*** (2.61)
Constant	0.337 (0.36)	1.179 (1.426)	-1.731* (0.988)	-0.767 (-0.96)
Control	Yes	Yes	Yes	Yes
Industry / Region / Year	Yes	Yes	Yes	Yes
N	10129	10129	10129	10129
Adj.R2	0.101	0.040	0.085	0.269

Descriptive statistics of the main variables_

Variable	Average	Standard	Min	Max
Innovation	2.469	1.591	0	6.727
Deg	0.024	0.016	0	0.074
Close	0.412	0.048	0.318	0.613
Scientific & technical writings	5.374	0.771	2.773	6.733
papers	10.676	.695	7.925	11.611
patent_applications	9.175	1.011	5.088	10.775
patent_transformation	4.377	0.936	0.693	5.308
alumni_patentApplictaions	6.681	1.085	1.386	8.153
academic_background	0.170	0.097	0	0.601
Age	3.952	0.101	3.664	4.174
Edu	1.366	0.196	0.693	1.609
Board	1.37	0.067	1.099	1.386
Cashflow	0.047	0.063	-0.138	0.216
TobinQ	1.076	0.345	0.607	2.252
ProfitRate	0.134	0.73	-6.499	2.49
LiauidityRatio	1.164	0.534	0.306	2.971
ROA	0.042	0.059	-0.271	0.183
TTM	0.269	0.138	0.022	0.636

Surrogate regression_

Variable	Innovation
	(1)	(2)	(3)	(4)
Close	-0.544** (-1.98)	-11.984*** (-4.43)	-13.707*** (-4.99)	-9.017*** (-3.60)
Close2		12.767*** (4.25)	15.01*** (4.92)	9.881*** (3.56)
Constant	2.721*** (23.91)	5.238*** (8.69)	-5.324*** (-5.04)	1.09 (1.14)
Control	Yes	Yes	Yes	Yes
Industry / Region / Year	No	No	No	Yes
N	10129	10129	10129	10129
Adj.R2	0.001	0.003	0.069	0.270

“U-shape” Relationship Test_

	Lower bound	upper bound
Interval	0.000	0.074
Slope	-11.314	8.858
t-value	-3.804	2.427
P > |t|	0.000	0.008
Overall test of presence of a U shape
t-value = 2.43
P > |t| = 0.008

Regression result of patent applications and transformations_

Variables	Innovation
	(1) Low	(2) Medium	(3) High	(4) Low	(5) Medium	(6) High
patent_applications	0.123** (2.02)	0.288*** (3.12)	0.115 (1.21)
patent_transfers				-0.007 (-0.36)	-0.018 (-0.78)	-0.046* (-1.93)
Constant	-2.323 (-1.56)	-2.058 (-1.13)	-4.735** (-2.54)	-1.377 (-0.96)	0.298 (0.18)	-3.568** (-2.10)
Control	Yes	Yes	Yes	Yes	Yes	Yes
Industry / Year	Yes	Yes	Yes	Yes	Yes	Yes
N	3886	3124	3119	3886	3124	3119
Adj.R2	0.205	0.266	0.266	0.203	0.262	0.268

Regression result of regulating effect_

Variables	Innovation
Deg	-20.032*** (-4.58)
Deg2	293.382*** (4.38)
academic_background	-0.492* (-1.75)
Deg*academic_background	53.69*** (2.80)
Deg2*academic_background	-977.138*** (-3.11)
Constant	-0.859 (-1.09)
Control	Yes
Industry / Year / Region	Yes
N	10129
Adj.R2	0.271

Regression result of papers and Scientific & technical writings_

Variables	Innovation
	(1) Low	(2) Medium	(3) High	(4) Low	(5) Medium	(6) High
papers	-0.007 (-0.09)	0.315 (1.40)	0.616*** (2.58)
Scientific & technical writings				0.139** (2.27)	0.189* (1.77)	-0.042 (-0.37)
Constant	-1.373 (-0.84)	-2.952 (-1.06)	-10.213*** (-3.39)	-1.997 (-1.39)	-.625 (-0.36)	-3.611** (2.03)
Control	Yes	Yes	Yes	Yes	Yes	Yes
Industry / Year	Yes	Yes	Yes	Yes	Yes	Yes
N	3886	3124	3119	3886	3124	3119
Adj.R2	0.203	0.262	0.269	0.205	0.263	0.265