VARIABLES | 国有 | 非国有 | Age > 20 | Age ≤ 20 | Size > 22 | Size ≤ 22 |
lnRD | lnRD | lnRD | lnRD | lnRD | lnRD | |
lnSub | 0.0307* | 0.0157 | 0.0316** | 0.0349 | 0.0252* | −0.0010 |
(1.73) | (0.88) | (2.23) | (1.50) | (1.94) | (−0.06) | |
Constant | −3.7437 | 8.7267*** | 2.5118 | 14.4252*** | 4.3466* | 11.9100*** |
(−0.76) | (2.98) | (0.84) | (5.09) | (1.91) | (2.80) | |
控制变量 | 控制 | 控制 | 控制 | 控制 | 控制 | 控制 |
观测值 | 201 | 360 | 411 | 150 | 314 | 247 |
R-squared | 0.681 | 0.817 | 0.721 | 0.842 | 0.712 | 0.569 |
Number of stkcd | 30 | 69 | 69 | 30 | 62 | 66 |
firm | yes | yes | yes | yes | yes | yes |
year | yes | yes | yes | yes | yes | yes |