Table 4.

Regression Adjusted Estimates of the Associations Between First Grade Achievement and Age-15 Mathematics Achievement

	Model 1		Model 2		Model 3		Model 4
	Age 15 Math (baseline)		Age 15 Math (mediators)		Age 15 Math (mediators + div/frac knowledge)		Coefficient Reduction from Model 1- Model 3
	b	s.e.	b	s.e.	b	s.e.	b	s.e.
First Grade Achievement
Mathematics	.36 ***	(.05)	.27 ***	(.05)	.22 ***	(.05)	.13 ***	(.02)
Reading	.10 *	(.04)	.10 *	(.04)	.05	(.04)
Mediators:
Math Self Concept Ability			.20 ***	(.02)	.16 ***	(.02)
School placements (2nd-4th grade)
Special education			−.13	(.09)	−.10	(.09)
Gifted and talented			.20 **	(.07)	.17 *	(.07)
Executive Function (3rd-4th grade)
Memory for Sentences			.08	(.05)	.08	(.05)
Tower of Hanoi			.03	(.03)	.01	(.03)
Continuous Performance Task			.04	(.04)	.03	(.03)
Division and Fractions Knowledge (5th grade)					.21 ***	(.03)
First Grade Executive Function
Memory for Sentences	.10 *	(.04)	.05	(.06)	.07	(.06)
Tower of Hanoi	.03	(.03)	.01	(.03)	.01	(.03)
Continuous Performance Task	.08 *	(.04)	.04	(.03)	.04	(.03)
Covariates	Inc.		Inc,		Inc.

Note. Continuous variables were standardized to z-scores using the means and standard deviations from each imputed data set (25 MI datasets; n=1362). Standard errors were obtained by the robust estimator. All coefficients were generated from fully controlled models. Covariates included first grade measures of externalizing, internalizing, and social skills; 54-month measures of surgency, negative affectivity, and effortful control; 36-month measure of school readiness (Bracken Basic Concept Scale), and 24-month measure of mental development (Bayley Mental Development Index); birth weight, ethnicity, gender, age at first grade test, number of children in the home, average family income between 1-month and first grade, mother's education level, mother's age at birth, and site. Model 4 was obtained by using Seemingly Unrelated Estimation (suest).

^*p ≤ .05;

^**p ≤ .01;

^***p ≤ .001.