Determination of the Influence of Fuel Switching Regulation on the Sulfur Dioxide Content of Air in a Port Area Using DID Model

Table 2

DID model results.

	No ship movement in or out of the dock (dt = 0)	Movement of ship(s) in or out of the dock (dt = 1)	Difference
	Monitoring point 1, March 2018
Downwind (treatment group, du = 1)	2.25	4.24	1.99
No wind (control group, du = 0)	3.18	1.42	−1.76
DID model estimation	−0.93	2.82	3.75
	Monitoring point 2, March 2018
Downwind (treatment group, du = 1)	5.06	5.35	0.29
No wind (control group, du = 0)	4.02	5.22	1.2
DID model estimation	1.04	0.13	−0.91
	Monitoring point 1, April 2018
Downwind (treatment group, du = 1)	3.56	3.86	0.3
No wind (control group, du = 0)	2.72	2.18	−0.54
DID model estimation	0.84	1.68	0.84
	Monitoring point 2, April 2018
Downwind (treatment group, du = 1)	4.33	4.61	0.28
No wind (control group, du = 0)	4.11	3.95	−0.16
DID model estimation	0.22	0.66	0.44
	Monitoring point 1, May 2018
Downwind (treatment group, du = 1)	3.25	3.71	0.46
No wind (control group, du = 0)	6.02	9.91	3.89
DID model estimation	−2.77	−6.2	−3.43
	Monitoring point 2, May 2018
Downwind (treatment group, du = 1)	3.52	4.15	0.63
No wind (control group, du = 0)	3.96	2.96	−1
DID model estimation	−0.44	1.19	1.63