. Author manuscript; available in PMC: 2019 Mar 11.

Published in final edited form as: Am Econ J Appl Econ. 2018 Jan;10(1):307–341. doi: 10.1257/app.20160404

Table 4.

Exploring Effects of Measurement Error in Lead Levels

	OLS (1)	OLS (2)	OLS (3)	OLS (4)
Panel A. Outcome = third grade reading score
Average of all capillary tests	−0.141 [0.0310]
Average of all venous tests		−0.313 [0.0470]
Single random draw of blood lead levels			−0.186 [0.0188]
Average all other blood lead levels				−0.278 [0.0238]
Observations	12,012	12,012	54,491	54,491
R²	0.226	0.229	0.233	0.234
Panel B. Outcome = third grade math score
Average of all capillary tests	−0.102 [0.0320]
Average of all venous tests		−0.201 [0.0477]
Single random draw of blood lead levels			−0.124 [0.0171]
Average all other blood lead levels				−0.189 [0.0212]
Observations	12,002	12,002	54,449	54,449
R²	0.221	0.223	0.232	0.233

Notes: Standard errors clustered on census tract are shown in brackets. Sample for columns 1–2 is limited to children from whom there are both capillary and venous measures of blood lead levels. Sample for columns 3–4 limited to children with at least two blood lead tests. All models include census tract, year of birth and month of birth fixed effects, as well as all other covariates listed in Table 3, column 3.