. 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 5.

OLS and IV Estimates of Lead and Third Grade Scores Instrument Is the Remaing Blood Lead Levels

	OLS (1)	IV (2)	IV (3)
Dependent variable: Below proficient in reading
Single random draw of blood lead levels	0.00465 [0.000600]	0.00961 [0.00121]	0.00873 [0.00120]
Observations	54,491	54,491	54,458
R²	0.093	0.037	0.047
Dependent variable: Reading score
Single random draw of blood lead levels	−0.186 [0.0188]	−0.442 [0.0372]	−0.396 [0.0372]
Observations	54,491	54,491	54,458
R²	0.233	0.107	0.123
Dependent variable: Below proficient in math
Single random draw of blood lead levels	0.00383 [0.000656]	0.00792 [0.00119]	0.00682 [0.00119]
Observations	54,449	54,449	54,416
R²	0.105	0.034	0.049
Dependent variable: Math score
Single random draw of blood lead levels	−0.124 [0.0171]	−0.305 [0.0351]	−0.266 [0.0347]
Observations	54,449	54,449	54,416
R²	0.232
Additional controls
Census tract, year of birth, month of birth fixed effects	Yes	Yes	Yes
Average score in grade × school (leave-out mean)			Yes
Percent below proficient in grade × school (leave-out mean)			Yes
Race specific linear time trend			Yes
Free lunch specific linear time trend			Yes

Notes: Standard errors clustered on census tract are in brackets. Instrument for child’s lead level is the average of the child’s other blood lead levels. All covariates in Table 3, column 3, also included. are relatively large effects compared to the baseline rates of 12 and 16 percent below proficiency in these subjects.