Table 2.

Effects of the Automobile NO_x Law on air pollutants.

		(1) NOx	(2) SO2	(3) Ox	(4) SPM	(5) NOx	(6) SO2	(7) Ox	(8) SPM
		[67.86]	[8.20]	[22.74]	[49.86]	[67.86]	[8.20]	[22.74]	[49.86]
Regulation		$-$3.388***	$-$0.893***	$-$1.098***	$-$1.480***	$-$3.458***	$-$0.893***	$-$1.100***	$-$1.450***
$\times$Post		(0.525)	(0.101)	(0.224)	(0.358)	(0.527)	(0.102)	(0.230)	(0.362)
Neighborhood						$-$0.653	0.001	$-$0.018	0.263
$\times$Post						(0.627)	(0.130)	(0.444)	(0.517)
Meteorological		Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Controls
Station FE		Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Year FE		Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Observations		14,085	13,743	9286	12,193	14,085	13,743	9286	12,193
Clusters		1312	1274	860	1186	1312	1274	860	1186
Adj.R-squared		0.9733	0.8227	0.6918	0.8510	0.9733	0.8227	0.6918	0.8510

Notes: Each dependent variable represents annual average concentration (ppb or $\mu \text{g}/{\text{m}}^3$). The mean values of the dependent variables in regulated areas in the pre-intervention period are reported in brackets. The meteorological control variables include the number of days with rainfall of over 1 mm, the number of days with a maximum wind speed of over 10 m/s, and the percentage of sunshine hours in a year. ***, **, and * represent statistical significance at the 1%, 5%, and 10% levels, respectively. Standard errors clustered at the monitoring station level are in parentheses.