. Author manuscript; available in PMC: 2024 Dec 1.

Published in final edited form as: Public Health. 2023 Nov 6;225:198–205. doi: 10.1016/j.puhe.2023.10.012

Table 2 –

First-Stage Effects of Instruments on Pollution Outcomes

Variable	Outcomes
	Ozone (STD)			PM₁₀ (STD)
	(1)	(2)	(3)	(4)	(5)	(6)
Precipitation (STD)	−.06188^***	−.06034^***	−.06505^***	−.12671^***	−.12511^***	−.12176^***
Precipitation (STD)	(.01668)	(.01657)	(.0167)	(.02969)	(.03062)	(.02726)
Observations	535,036	535,036	535,036	392,419	392,417	392,417
R-squared	.66233	.69027	.69406	.78829	.79629	.8035
County Fixed Effects	Yes	Yes	Yes	Yes	Yes	Yes
Year-Month Fixed Effects	Yes	Yes	Yes	Yes	Yes	Yes
County-by-Month Fixed Effects	No	Yes	Yes	No	Yes	Yes
County Controls	No	No	Yes	No	No	Yes

Notes. Standard errors, clustered at the county level, are in parentheses. The regressions are weighted using the total number of births in each county.

^***

p<0.01,

^**

p<0.05,

p<0.1

STD, standard deviation.