table 4

IV Estimates of the Impact of Prenatal Pollution Exposure on TLI Test Performance for the 1981–83 Birth Cohort

	(1)	(2)	(3)	(4)	(5)	(6)	(7)
	Main Results	Adding Employment	Additional Weather	Exogenous Income	No Income Control	Exogenous TSP	TLI Pass Rate
Panel A: Second-stage impacts
TSP	−0.0880***	−0.0649***	−0.0915**	−0.1226	−0.0676**	−0.0386***	−0.0027**
	(0.0311)	(0.0223)	(0.0421)	(0.0745)	(0.0328)	(0.0129)	(0.0012)
Impact of one Standard Deviation Δ in TSP
Δ in TLI score	−0.64	−0.47	−0.67	−0.89	−0.49	−0.28	−0.02
% s.d. in TLI	−5.57	−4.11	−5.79	−7.76	−4.27	−2.44	−5.17
Panel B: First-stage results and test statistics
Manf. Ratio	0.0061***	0.0054**	0.0052**	0.0061***	0.0044	.	0.0061***
	(0.0019)	(0.0021)	(0.0022)	(0.0019)	(0.0027)	.	(0.0019)
Test statistics
TSP AP	17.49	29.02	8.18	2.68	8.27	43.37	17.49
Income AP	25.08	28.64	28.16	.	.	.	25.08
KP F−statistic	4.34	4.34	2.57	1.19	4.45	33.16	4.34
SW p−value	0.0241	0.0241	0.0170	0.1261	0.2111	0.0279	0.0299
Observations	34,669	34,669	34,669	34,669	34,669	34,669	34,669
Total students	334,956	334,956	334,956	334,956	334,956	334,956	334,956

Notes: See table 3. Panel A shows second-stage regression results of the impact of TSPs in the year of birth on later test scores. Panel B shows first-stage results of the impact of an additional percent of employment in manufacturing on TSP levels. Column 1 is the primary result. Each additional column modifies Column 1 by including a control for nonmanufacturing employment divided by population (Column 2), including indicators for number of days above 85 and below 25 degrees Fahrenheit and days with windspeed above a 4 on the Beaufort scale (Column 3), treating income as exogenous and instrumenting for only TSPs (Column 4), excluding income from the regression entirely (Column 5), and treating TSPs as exogenous and instrumenting for only income (Column 6). Column 7 repeats Column 6 using the binary testpassage indicator as the outcome variable. First-stage test statistics used for weak instrument robust inference are discussed in Section VI. * significant at 10 percent; ** significant at 5 percent; *** significant at 1 percent.