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. Author manuscript; available in PMC: 2020 Mar 18.
Published in final edited form as: Am Econ Rev. 2019 Dec;109(12):4178–4219. doi: 10.1257/aer.20180279

Table 9—

Robustness of Mortality IV Estimates to Instrument Choices

(1) (2) (3) (4)
PM 2.5 (μg/m3) 0.690 0.719 0.652 0.603
(0.054) (0.056) (0.063) (0.067)
Size of wind angle bins (degrees) 60 90 90 90
Number of monitor groups 100 50 200 100
Interactions with season No No No Yes
F-statistic 197 554 161 NA
Dependent variable mean 385 385 385 385
Observations 1,980,549 1,980,549 1,980,547 1,980,549

Notes: Table reports IV estimates of equation (1) from the main text. The baseline specification reported in other tables aggregates pollution monitors into 100 groups and wind angles into 90-degree intervals. This table demonstrates that our estimates are not sensitive to the chosen level of aggregation or to interacting our instruments with seasonal indicators. The dependent variable is the three-day mortality rate per million Medicare beneficiaries. Estimates are weighted by the number of beneficiaries. Standard errors, clustered by county, are reported in parentheses.