原始观测值：5648
剔除关键变量缺失后：5457
剔除单例企业后（基准样本）：5457，企业数 500

交叉核对 (2) 列 DT 系数：PanelOLS=0.041166，LSDV=0.041166；聚类 SE：PanelOLS=0.008378，LSDV=0.008386（差异来自小样本自由度校正口径）

基准(2)：DT 每增加 1 个标准差，TFP_LP 变动（以 TFP_LP 标准差计）: 0.0605
基准(2)：DT 每增加 1 个标准差，TFP_LP 变动（对数点）: 0.0399
稳健(1)：DT 每增加 1 个标准差，TFP_OP 变动（以 TFP_OP 标准差计）: 0.0532
稳健(2)：DT_Asset 每增加 1 个标准差，TFP_LP 变动（以 TFP_LP 标准差计）: 0.0294

===== 基准 (2) 完整输出 =====
                          PanelOLS Estimation Summary                           
================================================================================
Dep. Variable:                 tfp_lp   R-squared:                        0.3267
Estimator:                   PanelOLS   R-squared (Between):              0.8848
No. Observations:                5457   R-squared (Within):               0.4156
Date:                Tue, Oct 20 2026   R-squared (Overall):              0.8836
Time:                        02:22:12   Log-likelihood                   -616.25
Cov. Estimator:             Clustered                                           
                                        F-statistic:                      266.12
Entities:                         500   P-value                           0.0000
Avg Obs:                       10.914   Distribution:                  F(9,4937)
Min Obs:                       6.0000                                           
Max Obs:                       12.000   F-statistic (robust):             223.99
                                        P-value                           0.0000
Time periods:                      12   Distribution:                  F(9,4937)
Avg Obs:                       454.75                                           
Min Obs:                       363.00                                           
Max Obs:                       489.00                                           
                                                                                
                             Parameter Estimates                              
==============================================================================
            Parameter  Std. Err.     T-stat    P-value    Lower CI    Upper CI
------------------------------------------------------------------------------
dt             0.0412     0.0084     4.9136     0.0000      0.0247      0.0576
size           0.2134     0.0051     41.589     0.0000      0.2034      0.2235
lev           -0.2334     0.0241    -9.6995     0.0000     -0.2806     -0.1862
roa            1.1544     0.0891     12.953     0.0000      0.9797      1.3291
growth         0.0808     0.0132     6.1253     0.0000      0.0550      0.1067
top1          -0.0200     0.0316    -0.6321     0.5274     -0.0820      0.0420
board         -0.0150     0.0119    -1.2559     0.2092     -0.0384      0.0084
indep         -0.0064     0.0913    -0.0700     0.9442     -0.1854      0.1726
age            0.0927     0.0472     1.9659     0.0494      0.0003      0.1852
==============================================================================

F-test for Poolability: 20.967
P-value: 0.0000
Distribution: F(510,4937)

Included effects: Entity, Time

===== 稳健(1) =====
                             Parameter Estimates                              
==============================================================================
            Parameter  Std. Err.     T-stat    P-value    Lower CI    Upper CI
------------------------------------------------------------------------------
dt             0.0321     0.0096     3.3533     0.0008      0.0133      0.0508
size           0.1727     0.0059     29.432     0.0000      0.1612      0.1842
lev           -0.1989     0.0270    -7.3529     0.0000     -0.2519     -0.1458
roa            0.9069     0.0995     9.1183     0.0000      0.7119      1.1018
growth         0.0651     0.0149     4.3661     0.0000      0.0359      0.0944
top1          -0.0105     0.0356    -0.2956     0.7676     -0.0804      0.0593
board         -0.0201     0.0136    -1.4777     0.1396     -0.0467      0.0066
indep         -0.0127     0.1046    -0.1209     0.9037     -0.2178      0.1925
age            0.0825     0.0519     1.5892     0.1121     -0.0193      0.1843
==============================================================================

===== 稳健(2) =====
                             Parameter Estimates                              
==============================================================================
            Parameter  Std. Err.     T-stat    P-value    Lower CI    Upper CI
------------------------------------------------------------------------------
dig_asset      0.0075     0.0023     3.3042     0.0010      0.0030      0.0119
size           0.2133     0.0051     41.706     0.0000      0.2033      0.2234
lev           -0.2312     0.0241    -9.5802     0.0000     -0.2786     -0.1839
roa            1.1599     0.0893     12.985     0.0000      0.9848      1.3351
growth         0.0806     0.0132     6.0900     0.0000      0.0547      0.1066
top1          -0.0176     0.0317    -0.5552     0.5788     -0.0799      0.0446
board         -0.0157     0.0120    -1.3036     0.1924     -0.0392      0.0079
indep         -0.0064     0.0915    -0.0698     0.9444     -0.1857      0.1729
age            0.0955     0.0476     2.0055     0.0450      0.0021      0.1889
==============================================================================

===== 稳健(3) =====
                             Parameter Estimates                              
==============================================================================
            Parameter  Std. Err.     T-stat    P-value    Lower CI    Upper CI
------------------------------------------------------------------------------
L_dt           0.0513     0.0095     5.4182     0.0000      0.0328      0.0699
size           0.2142     0.0053     40.147     0.0000      0.2038      0.2247
lev           -0.2306     0.0260    -8.8706     0.0000     -0.2816     -0.1797
roa            1.1866     0.0929     12.775     0.0000      1.0045      1.3687
growth         0.0780     0.0142     5.4928     0.0000      0.0501      0.1058
top1          -0.0282     0.0343    -0.8223     0.4109     -0.0956      0.0391
board         -0.0159     0.0134    -1.1869     0.2353     -0.0422      0.0104
indep         -0.0621     0.0956    -0.6495     0.5160     -0.2494      0.1253
age            0.0595     0.0599     0.9930     0.3208     -0.0580      0.1771
==============================================================================

===== 稳健(4) =====
                             Parameter Estimates                              
==============================================================================
            Parameter  Std. Err.     T-stat    P-value    Lower CI    Upper CI
------------------------------------------------------------------------------
L_dt           0.0585     0.0113     5.1525     0.0000      0.0362      0.0807
L_size        -0.0207     0.0061    -3.3791     0.0007     -0.0326     -0.0087
L_lev          0.0354     0.0352     1.0051     0.3149     -0.0336      0.1043
L_roa         -0.2043     0.1047    -1.9522     0.0510     -0.4095      0.0009
L_growth       0.0004     0.0178     0.0246     0.9804     -0.0344      0.0353
L_top1         0.0095     0.0389     0.2430     0.8080     -0.0668      0.0857
L_board       -0.0271     0.0152    -1.7868     0.0740     -0.0569      0.0026
L_indep        0.0701     0.1091     0.6428     0.5204     -0.1437      0.2840
L_age          0.0124     0.0592     0.2099     0.8338     -0.1036      0.1284
==============================================================================
