Table 1.

Descriptive statistics for the variables.

Variable	Grouping	Mean	SD	Min	Max	Observations
Perinatal mortality rates (‰)	Overall	9.129	4.547	2.150	25.800	N = 434
	Between		3.618	2.876	20.935	n = 31
	Within		2.824	2.215	20.538	T = 14
Average PM2.5 (log)	Overall	3.745	0.484	2.183	4.519	N = 434
	Between		0.479	2.351	4.391	n = 31
	Within		0.108	3.186	4.208	T = 14
Max PM2.5 (log)	Overall	3.987	0.416	2.666	4.718	N = 434
	Between		0.405	2.890	4.544	n = 31
	Within		0.117	3.430	4.578	T = 14
New Average PM2.5 (log)	Overall	3.500	0.581	1.462	4.426	N = 434
	Between		0.573	1.650	4.256	n = 31
	Within		0.141	2.946	4.055	T = 14
New Max PM2.5 (log)	Overall	4.288	0.339	3.114	5.956	N = 434
	Between		0.298	3.255	4.775	n = 31
	Within		0.170	3.863	6.038	T = 14
GDP per capita(log)	Overall	4.701	0.672	2.790	6.107	N = 434
	Between		0.478	3.813	5.671	n = 31
	Within		0.480	3.492	5.618	T = 14
bed_pop	Overall	35.675	10.809	15.318	63.671	N = 434
	Between		6.171	27.839	49.940	n = 31
	Within		8.939	21.434	61.823	T = 14
ha_pop	Overall	5.038	3.446	1.231	21.789	N = 434
	Between		1.957	1.697	12.439	n = 31
	Within		2.856	− 2.860	14.388	T = 14
Urbanization rate (%)	Overall	48.327	15.252	13.890	89.600	N = 434
	Between		13.112	22.351	84.071	n = 31
	Within		8.115	− 11.190	85.220	T = 14