Sulfur dioxide emission intensity

lnSI

Industrial soot emission intensity

lnMI

Model (1)

Model (2)

Model (1)

Model (2)

Independent variable

Policy_t

−0.0562

(−0.72)

−0.7628

(−1.36)

0.5087**

(2.60)

0.6305

(0.62)

YRD_i × Policy_t

−0.0823

(−0.95)

−0.0678

(−0.79)

−0.2638

(−1.14)

−0.3065

(−1.32)

PRD_i × Policy_t

−0.0810

(−0.66)

−0.0716

(−0.59)

−0.1703

(−0.59)

−0.2058

(−0.69)

Control variable

lnPGDP_it

−0.3019*

(−1.82)

−0.3224

(−1.63)

−0.8729***

(−4.94)

−0.8490***

(−4.46)

lnSTR_it

1.9302***

(4.63)

1.5978***

(3.45)

1.5759**

(2.48)

1.6840**

(2.41)

lnPOP_it

−0.5553

(−1.29)

−0.5333

(−1.23)

−0.9984

(−1.23)

−0.9603

(−1.18)

lnUR_it

−0.1938***

(−3.34)

−0.2360***

(−3.83)

−0.0921

(−0.51)

−0.1912

(−1.03)

lnSC_it

−0.0614

(−1.08)

−0.0173

(−0.30)

−0.1432

(−1.48)

−0.1537

(−1.52)

lnFE_it

−0.3503**

(−2.35)

−0.0142

(−0.06)

0.2944

(1.51)

0.2174

(0.57)

lnRD_it

−0.0685**

(−2.32)

−0.0832*

(−1.75)

−0.1308***

(−3.07)

−0.0427

(−0.50)

lnFI_it

−0.0007

(−0.01)

−0.0364

(−0.72)

−0.0759

(−1.00)

−0.0662

(−0.86)

Constant term

3.7868

(1.04)

3.5342

(0.99)

8.8953

(1.45)

8.6585

(1.41)

Time Effect

√

√

Individual Effect

√

√

√

√

Observations

689

689

689

689

Within R²

0.7636

0.7838

0.2962

0.3465