Table 3. Second-stage stochastic frontier analysis regression results.

Variables	Number of staffs	Total assents	Operating cost
Constant (β0)	-362.76*** (-221.31)	380.44*** (196.19)	597.32*** (462.77)
Years of incorporation (β1)	112.13*** (217.43)	-471.31*** (-342.18)	17.54*** (111.33)
Ownership concentration (β2)	-92.11*** (-200.76)	12.53*** (96.82)	464.98*** (804.64)
Equity restriction ratio (β3)	9.26*** (46.58)	3.83*** (102.33)	10.14*** (58.83)
Internet development index (β4)	60.33*** (22.31)	-582.43*** (-298.96)	-154.56*** (-128.38)
Regional openness degree (β5)	1.32*** (6.56)	2.30*** (1.53)	3.61*** (4.89)
${\sigma }^2={\sigma }_v^2+{\sigma }_{\mu }^2$	877299.00*** (877299.00)	33719.00*** (33719.00)	58051.00*** (58051.00)
$\gamma ={\sigma }_{\mu }^2+{\sigma }^2$	1.00*** (843513.00)	1.00*** (83668.66)	1.00*** (576.22)
Log likelihood function	-760.46	-579.71	-522.53

Note:

(***), (**), and (*) respectively represent significance at the 1%, 5%, and 10% level.