. 2023 Jan 28;42(1):4. doi: 10.1007/s11113-023-09759-1

Table 2.

Main results

Variable	(1)	(2)	(3)	(4)	(5)
Variable	Birth weight (g)	Birth weight (g)	Birth weight (g)	Birth weight (dummy)	Birth weight (dummy)
$T_{it}^{1}$	− 9.647**	− 3.036	− 4.225*	− 0.001	− 0.000 +
$T_{it}^{1}$	(2.030)	(1.927)	(1.864)	(0.001)	(0.000)
$T_{it}^{2}$	− 18.422**	− 19.776**	− 19.791**	0.001	− 0.000
$T_{it}^{2}$	(1.689)	(2.608)	(2.521)	(0.001)	(0.000)
$T_{it}^{1}$ $\times$ $T_{it}^{2}$	7.370**	6.547**	6.517**	− 0.001	0.000
$T_{it}^{1}$ $\times$ $T_{it}^{2}$	(2.448)	(2.322)	(2.246)	(0.001)	(0.000)
Female		− 112.658**	− 105.935**	0.010**	− 0.000
Female		(1.077)	(1.041)	(0.000)	(0.000)
Birth in a clinic		16.260 +	16.236 +	0.000	0.000**
Birth in a clinic		(9.225)	(8.955)	(0.003)	(0.000)
Birth after marriage		29.955**	24.812**	− 0.006**	0.000**
Birth after marriage		(4.728)	(4.506)	(0.002)	(0.000)
Birth within 2 years		− 8.467**	− 7.197**	0.002**	0.000*
Birth within 2 years		(1.353)	(1.305)	(0.001)	(0.000)
Total births		47.834**	40.577**	− 0.009**	− 0.000 +
Total births		(1.046)	(1.009)	(0.000)	(0.000)
Father’s schooling		9.340**	10.065**	0.000	0.000
Father’s schooling		(1.504)	(1.452)	(0.001)	(0.000)
Mother’s schooling		6.716**	9.107**	0.002**	− 0.000
Mother’s schooling		(1.637)	(1.578)	(0.001)	(0.000)
Father’s age		− 1.012	− 1.338	− 0.000	0.000
Father’s age		(1.159)	(1.113)	(0.000)	(0.000)
Father’s age squared		0.010	0.017	0.000	− 0.000
Father’s age squared		(0.016)	(0.015)	(0.000)	(0.000)
Mother’s age		14.079**	11.781**	− 0.003**	0.000
Mother’s age		(1.520)	(1.459)	(0.001)	(0.000)
Mother’s age squared		− 0.190**	− 0.149**	0.000**	0.000
Mother’s age squared		(0.023)	(0.022)	(0.000)	(0.000)
Birth month FE	N	Y	Y	Y	Y
Birth region FE	N	Y	Y	Y	Y
Gestational period FE	N	Y	Y	Y	Y
R²	0.000	0.105	0.092	0.020	0.000
N	438,192	434,355	426,385	434,355	434,355

The estimation is based on the difference-in-difference method. Column (1) shows the results when the covariates are not controlled, and Column (2) shows the results when including all control variables. Column (3) shows the results when limiting the sample to those whose birth weight was greater than 2500 g. We employed the dependent variable of birth weight (g) in Columns (1) to (3) and the dummy variable indicating low-birth weight infants in Columns (4) and (5), which is equal to 1 if newborns were less than 2500 g or 1500 g at birth, respectively

Robust standard errors in parentheses, + p < 0.10, *p < 0.05, **p < 0.01