Table 1.

Estimated Effect of Age 19/20 Frequency of Marijuana Use on Bachelor’s Degree Attainment by Age 23/24 (Full Longitudinal Sample): Logistic Regression and Propensity Score Analyses

	Estimated Proportion with Bachelor’s degree or higher
	No/Less Use	More Use	z	p
Non-Users vs Infrequent Users (n=4,466)
Logistic regressions
No Controls	0.386	0.421	−1.38	0.168
With age 18 risk factor controlsa	0.308	0.332	−0.75	0.456
With age 18 risk factor + SUb controls	0.303	0.337	−1.01	0.312
Propensity models
Matched on age 18 risk factors	0.493	0.450	−1.37	0.170
Matched on age 18 risk factors + SU	0.425	0.450	0.87	0.386
Non-Users vs Frequent Users (n=4,452)
Logistic regressions
No Controls	0.386	0.295	3.36	0.001
With age 18 risk factor controls	0.300	0.218	2.76	0.006
With age 18 risk factor + SUa controls	0.293	0.242	1.24	0.214
Propensity models
Matched on age 18 risk factors	0.386	0.312	−2.45	0.014
Matched on age 18 risk factors + SU	0.349	0.312	−0.92	0.357
Infrequent Users vs Frequent Users (n=932)
Logistic regressions
No Controls	0.421	0.295	3.58	0.000
With age 18 risk factor controls	0.323	0.235	2.28	0.023
With age 18 risk factor + SUa controls	0.292	0.232	1.44	0.150
Propensity models
Matched on age 18 risk factors	0.375	0.312	−0.064	0.057
Matched on age 18 risk factors + SU	0.303	0.312	0.009	0.820

^aAge 18 risk factor controls: gender, race/ethnicity, parent education, family structure, region of country, public high school, college prep curriculum, grade point average, academic ability, 4-yr college plans, other post-high-school training plans, hours worked for pay, evenings out, and truancy.

^bSU=Substance use: Age 18 30-day tobacco use, alcohol use and marijuana use.