Absence of conflict of interest.
Bowers, J. M. (2018). Does stacking work? The academic value of short-term, stackable certificates (Unpublished doctoral dissertation). University of Washington, Seattle, WA.
- The study’s objective was to evaluate the benefits of stackable certificates on education and earnings outcomes for full-time students with no prior post-secondary education.
- The author used a nonexperimental design to compare the effects of participating in stackable short-term certificate programs on outcomes for those in the treatment group versus those in the comparison group.
- The study found that students who attained a single short-term stackable certificate had a sufficiently lower likelihood of earning a two-year degree, whereas attaining two or more short-term, stackable certificates more than doubled a student’s likelihood of earning a degree.
- The quality of causal evidence presented in this study is moderate because it was based on a well-implemented nonexperimental design. This means we are somewhat confident that the estimated effects are attributable to short-term stackable certificates, but other factors might also have contributed.
Short-Term Stackable Certificates
Features of the Intervention
Short-term certificates are academic awards that require less than one-year of full-time, college-level study and are the quickest job market training solution for professional/technical fields. The concept of stackable short-term certificates breaks down two-year degrees and other longer-to-complete academic awards into smaller, “stepping stone” awards with the idea that it will increase the likelihood of students progressing past the initial short-term certificate toward a two-year degree. To be eligible for the stackable certificates, community college students had to be part of a certificate program in nursing, business IT or management, automotive technology, welding, accounting, early childhood education, computer IT, or autobody collision/repair.
Features of the Study
The study was a nonexperimental design using data from 33 Washington State community and technical colleges. The study included 3,573 professional/technical students from the 2007-08 entry cohort, with no prior higher education and enrolled full-time in a short-term stackable certificate program. Students were categorized by their stackable short-term certificate status and coded as: progression stacking (earned two or more short-term certificates in the same program of study), potential stacking (earned one short-term certificate with the potential to stack but did not stack within the 5-year follow-up period), independent stacking (earned two or more short-term certificates in different programs of study) or no stacking (earned at least 15 credits with at least one in the declared program of study). Students with a no stacking status were used as the comparison group. Outcomes included degree attainment status, total credits earned, post-college inflation-adjusted earnings, and pre-and post-college inflation-adjusted earnings difference. The author used a 5-year follow-up period to recognize students who need to complete remedial studies prior to earning a degree. The author used statistical models with controls for gender, age, ethnicity, financial need status, college campus, and program of study to examine the impact of short-term stackable certificates on student outcomes.
Education and skills gain
- Progression stacking (students who earned two or more short-term certificates in the initial program area of study) had a significant positive effect on the likelihood of earning a degree and the total number of credits earned when compared to cases where no short-term certificate was earned.
- Progression stacking also significantly increased the likelihood of earning a degree by 30 percentage points compared to the overall average.
- Potential stacking (students who earned just one short-term certificate) was not significantly related to earning a degree or the number of credits earned.
- Independent stacking (students who earned two or more short-term certificates from different fields of study) was not significantly related to earning a degree.
Earnings and wages
- There was no significant relationship between attaining a short-term, stackable certificate (one or more) and earnings.
Considerations for Interpreting the Findings
Although the author used a well-implemented nonexperimental design, treatment group participants self-selected into the short-term stackable certificate programs. Students who self-selected into the programs could differ in observable and unobservable ways, affecting the observed outcomes.
Causal Evidence Rating
The quality of causal evidence presented in this study is moderate because it was based on a well-implemented nonexperimental design. This means we are somewhat confident that the estimated effects are attributable to short-term stackable certificates, but other factors might also have contributed.