Table 13.

IV estimates (PM2.5, PM10, and SO2)

	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
	OLS	OLS Pref	OLS	IV	OLS	IV	OLS	IV
WBT	$-$107.325${}^{\ast \ast \ast }$	$-$78.001${}^{\ast \ast \ast }$	$-$80.104${}^{\ast \ast \ast }$	$-$166.606${}^{\ast \ast \ast }$	$-$79.307${}^{\ast \ast \ast }$	$-$154.121${}^{\ast \ast \ast }$	$-$89.253${}^{\ast \ast \ast }$	$-$123.465${}^{\ast \ast \ast }$
	(13.992)	(9.869)	(12.377)	(33.346)	(12.409)	(29.006)	(12.879)	(19.318)
PM2.5	Yes	No	Yes	Yes	No	No	No	No
PM10	Yes	No	No	No	Yes	Yes	No	No
SO${}_2$	Yes	No	No	No	No	No	Yes	Yes
NO${}_2$	Yes	No	No	No	No	No	No	No
CO	Yes	No	No	No	No	No	No	No
O${}_3$	Yes	No	No	No	No	No	No	No
Obs	24,546	35,190	24,546	24,546	24,546	24,546	24,546	24,546
No. of workers	437	635	437	437	437	437	437	437