TABLE 4.

Indicator variable intercepts from longitudinal confirmatory factor analysis models of neighborhood socio-economic status in which indicator variable intercepts are unconstrained (model B3) versus constrained (models B4 and C1)

Variable	Indicator intercepts unconstrained			Indicator intercepts constrained
	Model B3a			Model B4b	Model C1c
	1990	2000	2008–2012	All time points	All time points
Median household income	10.47	10.47	10.47	10.47	10.47
Educational level	9.39	9.61	11.06	10.35	9.39
Unemployment	−2.70	−2.67	−2.32	−2.59	−2.70
Female-headed households	−2.30	−2.20	−2.26	−2.28	−2.30
Poverty	−1.55	−1.45	−1.44	−1.50	−1.55

All indicator intercepts are highly statistically significant (p < 0.0001)

^aModel B3 is estimated using five indicator variables for the socio-economic status of U.S. census tracts, with correlated errors of two of the indicator variables and constraints on the factor loadings (not shown) for each respective indicator to be equal over time. Median household income is selected as the reference variable and 1990 is selected as the reference time point for statistical identification of all models; thus the indicator intercepts for median household income are constrained to their 1990 value at each time point

^bModel B4 adds to model B3 constraints on the intercepts for each respective indicator to be equal over time

^cModel C1 is equivalent to model B4, and also adjusts the model for strong invariance over time