Can Highway Networks Promote Productivity? Evidence from China

Table 4

Statistical description of the main variables.

Name	Description	Mean	Standard deviation
TFP	Log of enterprise total factor productivity	3.2084	1.1014
Traveltime	Log of travel time to various cities	8.9189	0.2715
MP	Log of market potential	12.3972	0.6102
Age	Log of enterprise age	1.9973	0.7960
Scale	Log of total enterprise assets	9.8982	1.5983
Export	Ratio of export delivery value to gross industrial output	0.1498	0.3358
Own state	Ratio of state-owned capital to the total assets of the enterprise	0.0468	0.2004
GDP	Log of GDP	7.4207	1.1388
R&D	Log of city R&D capital	11.89178	2.3912
POP	Log of population	8.1434	1.8344
FDI	Log of direct foreign investment	12.9379	1.9006
Railway	Log of ordinary railway mileage	5.3951	0.9881