Working Paper: NBER ID: w29254
Authors: Jack Mountjoy
Abstract: Two-year community colleges enroll nearly half of all first-time undergraduates in the United States, but to ambiguous effect: low persistence rates and the potential for diverting students from 4-year institutions cast ambiguity over 2-year colleges' contributions to upward mobility. This paper develops a new instrumental variables approach to identifying causal effects along multiple treatment margins, and applies it to linked education and earnings registries to disentangle the net impacts of 2-year college access into two competing causal margins: significant value-added for 2-year entrants who otherwise would not have attended college, but negative impacts on students diverted from immediate 4-year entry.
Keywords: community colleges; upward mobility; educational attainment; instrumental variables
JEL Codes: C31; C36; I23; I24; I26; J24; J31
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| 2-year college access (I23) | educational attainment (I21) |
| 2-year college access (I23) | earnings (J31) |
| 2-year college access (I23) | diversion from 4-year entry (Y40) |
| diversion from 4-year entry (Y40) | lower educational attainment (I24) |
| diversion from 4-year entry (Y40) | lower earnings (J31) |
| 2-year college access (I23) | significant gains for new entrants (L26) |
| demographics (women) (J21) | larger effects from 2-year college access (D29) |
| low-income students (I24) | benefit from 2-year access (Y20) |