Absence of conflict of interest.
Reder, S. (2014). The impact of ABS program participation on long-term economic outcomes. Washington, DC: United States Department of Education, Office of Career, Technical and Adult Education.
- The study’s objective was to examine the impact of Adult Basic Skills (ABS) training on earnings and wages.
- The author used a nonexperimental design to compare the outcomes of adults who participated in various levels of ABS training to a matched comparison group who did not, over a ten-year time period.
- The study found a significant relationship between participating in ABS training and higher income, with a greater increase in income for those with at least 100 hours of ABS training. The study also found that wages were significantly associated with the length of time since training and intensity of training, with higher wages among participants who had attained 100 hours of ABS training in earlier years.
- The quality of causal evidence presented in this report is low because the author did not ensure that the groups being compared were similar before the intervention. This means we are not confident that the estimated effects are attributable to Adult Basic Skills training; other factors are likely to have contributed.
Features of the Study
The nonexperimental study compared the outcomes of adults (ages 18-44) who participated in Adult Basic Skills (ABS) training to those who did not, using data from the Longitudinal Study of Adult Learning (LSAL). The LSAL randomly sampled high school dropouts who lived in Portland, Oregon and followed them from 1998–2007. The sample included adults who had not completed high school nor were enrolled in high school; were not enrolled in college; and were proficient English speakers, including non-native English speakers. The LSAL conducted in-home interviews and skills assessments to evaluate literacy skills, as well as changes in social, educational, and economic status.
In the present study, the author compared the change in wages for the treatment group and a matched comparison group over a ten-year study period. The study assessed the effects of ABS training, but did not focus on a specific program or organization offering the training. The treatment group consisted of adults who participated in ABS training. The author matched ABS training participants to similar nonparticipants using propensity scores developed from demographic information. The analysis sample included a total of 1,020 participants; 510 participants in the treatment group and 510 participants in the comparison group.
In addition to LSAL data, the study used unemployment insurance and wage data from Oregon and Washington State. The author used difference-in-differences models to compare the wages of those who participated in any ABS training (at least 1, 25, 75, 100 or 150 hours) to the comparison group, and the wages of those who participated in at least 100 hours of ABS training to the comparison group. The author also explored the relationship between ABS training participation (hours and years participating) and wages, controlling for changes over time.
Earnings and wages
- The study found that ABS training was significantly associated with a greater increase in income from 1997 (year prior to LSAL) to 2007 for those with at least 100 hours of ABS training compared to those who did not participate in ABS training.
- However, no significant relationship was found between ABS training participation (defined as at least 1, 25, 75, 100 or 150 hours) and income.
- The study found that both the intensity of training and elapsed time since the onset of participation was significantly related to wages; the more time elapsed since an individual accumulated 100 hours of training, the greater the individual’s earnings tended to be.
Considerations for Interpreting the Findings
The author matched the treatment and comparison groups on age, gender, race/ethnicity, income in the year prior to the study, and other characteristics. However, the author did not control for previous earnings greater than one year before program participation as required by the protocol. These preexisting differences between the groups—and not the ABS training— could explain the observed differences in outcomes. Therefore, the study is not eligible for a moderate causal evidence rating, the highest rating available for nonexperimental designs.
Causal Evidence Rating
The quality of causal evidence presented in this report is low because the author did not ensure that the groups being compared were similar before the intervention. This means we are not confident that the estimated effects are attributable to Adult Basic Skills training; other factors are likely to have contributed.