TABLE 4.

Effects on low birthweight for mothers with different characteristics (models with mother fixed effects and 39 weeks IV)

Mom CHAR:	HS or less	Black	Hispanic	Over 35	Teen mom	Smoking
Panel A: Cluster S.E. on Mother
Any chem.	− 0.0010	0.0018	0.0033+	0.0034+	0.0035**	0.0032+
	(0.0021)	(0.0018)	(0.0020)	(0.0018)	(0.0017)	(0.0017)
* Mom CHAR	0.0098**	0.0075	0.0003	0.0009	− 0.0101	0.0067
	(0.0034)	(0.0048)	(0.0037)	(0.0075)	(0.0197)	(0.0124)
Any contam.	− 0.0003	0.0021	0.0033+	0.0031**	0.0033**	0.0029+
	(0.0019)	(0.0016)	(0.0018)	(0.0016)	(0.0015)	(0.0015)
* Mom CHAR	0.0085**	0.0057	− 0.0001	0.0018	− 0.0043	0.0105
	(0.0031)	(0.0046)	(0.0035)	(0.0062)	(0.0194)	(0.0110)
No. observations	521978	521978	521978	521978	521978	521978
Panel B: Cluster S.E. on water district and year
Any chem.	− 0.0008	0.0020	0.0037+	0.0036**	0.0037**	0.0034**
	(0.0018)	(0.0017)	(0.0019)	(0.0017)	(0.0017)	(0.0017)
* Mom CHAR	0.0097***	0.0077**	− 0.0001	0.0009	− 0.0104	0.0069
	(0.0022)	(0.0036)	(0.0029)	(0.0051)	(0.0132)	0.0101041
Any contam.	− 0.0001	0.0023	0.0036**	0.0033**	0.0035+	0.0031+
	(0.0015)	(0.0014)	(0.0016)	0.0014851	(0.0015)	0.0014653
* Mom CHAR	0.0086***	0.0060+	− 0.0004	0.0018	− 0.0046	0.01067
	(0.0021)	(0.0035)	(0.0027)	0.0042656	(0.0134)	0.0089193
No. observations	521978	521978	521978	521978	521978	521978

NOTES: See table 3 notes. Mother characteristics are measured as of the first birth. Robust standard errors are clustered on the mother.