TABLE 7.

Propensity Score Balance Diagnostics

	Number of adolescents
	No LD	LD		Percentage of covariates in each block balanced
Block 1	2,150	10		98%
Block 2	3,490	60		95%
Block 3	3,690	120		100%
Block 4	1,940	100		100%
Block 5	1,010	90		100%
Block 6	1,070	110		100%
Block 7	1,030	170		100%
Block 8	320	80		95%
Block 9	60	30		99%
Block 10	20	10		100%
	Propensity score
	No LD		LD
	Mean	(SD)	Mean	(SD)
Block 1	0.01	(0.00)	0.01	(0.00)
Block 2	0.02	(0.00)	0.02	(0.00)
Block 3	0.03	(0.01)	0.03	(0.01)
Block 4	0.05	(0.01)	0.05	(0.01)
Block 5	0.07	(0.02)	0.07	(0.01)
Block 6	0.09	(0.03)	0.09	(0.01)
Block 7	0.12	(0.08)	0.13	(0.02)
Block 8	0.20	(0.00)	0.21	(0.04)
Block 9	0.30	(0.00)	0.31	(0.05)
Block 10	0.36	(0.01)	0.41	(0.06)
Dependent variable: Ninth-grade math higher than normative
	No LD		LD
	Mean	(SD)	Mean	(SD)
Block 1	0.83	(0.37)	0.67	(0.48)
Block 2	0.56	(0.50)	0.40	(0.49)
Block 3	0.34	(0.48)	0.22	(0.42)
Block 4	0.23	(0.42)	0.20	(0.40)
Block 5	0.17	(0.38)	0.19	(0.39)
Block 6	0.16	(0.36)	0.12	(0.32)
Block 7	0.16	(0.37)	0.11	(0.32)
Block 8	0.10	(0.30)	0.09	(0.29)
Block 9	0.17	(0.37)	0.13	(0.34)
Block 10	0.08	(0.27)	0.25	(0.44)

Source. U.S. Department of Education, National Center for Education Statistics, “The High School Longitudinal Study of 2009.”

Note. Balance means that the difference in the mean level of the measure of interest is not statistically significant for treatment and control cases in the same block. Stata’s pscore command constructs enough blocks to ensure balanced propensity scores. LD = learning disability; SD = standard deviation.

^***p<0.001.

^**p<0.01.

^*p<0.05.

⁺p<0.10.