Exhibit 1.

Sociodemographic characteristics of 316,600 women delivering in New York City in 2012–14, by racial and economic spatial polarization measures

		ICE Race		ICE Income		ICE Race-Income
Characteristics	No.	Quintile 1 (n = 69,437)	Quintile 5 (n = 37,824)	Quintile 1 (n = 107,038)	Quintile 5 (n = 34,088)	Quintile 1 (n = 84,597)	Quintile 5 (n = 36,341)
Race/ethnicity
Black	66,281	58%	3%	28%	5%	50%	3%
Latina	98,569	29	11	44	9	41	9
Non-Latina white	95,708	8	71	14	69	6	71
Asian	56,042	5	15	15	17	4	16
Age, years
Less than 20	14,221	7	1	7	1	8	1
20 to less than 35	231,732	74	63	77	59	75	60
35 to less than 40	54,713	14	27	13	30	13	30
40 or more	15,934	4	8	4	10	4	9
Born in US
No	154,629	47	33	51	26	48	27
Yes	161,971	53	67	49	74	52	73
Education
Less than high school	68,220	23	5	32	3	28	3
High school	71,457	26	7	29	4	27	5
Some college	71,523	31	13	25	9	30	10
College or more	105,400	20	75	15	84	16	82
Insurance during pregnancy
Medicaid	199,977	75	19	83	10	80	11
Private or other	116,623	25	81	17	90	20	89
Previous live births
No	142,056	42	58	40	62	41	61
Yes	174,544	58	42	60	38	59	39

SOURCE Authors’ analysis of New York City birth certificate and hospital discharge data linked to American Community Survey data.

NOTES The Index of Concentration at the Extremes (ICE) measure for race (ICE Race) is the relative concentration of non-Hispanic black to non-Hispanic white populations in the mother’s or hospital’s ZIP code. The ICE measure for income (ICE Income) is the relative concentration of low-income households to high-income households in a ZIP code. The ICE measure for race and income (ICE Race-Income) is the relative concentration of low-income black households to high-income white households in a ZIP code. For all three indices, quintile 1 is the highest relative concentration and quintile 5 is the lowest. Chi-square bivariate tests of frequencies of all characteristics by each ICE measure were significant (p < 0.001).