The conclusion seems to be that there is not a "right way" to improve college success. If students are 4 year college bound, AP is better. If they are looking at associates degrees, DE is the way to go. And all students need to be better prepared for both.
"The study finds that both AP and DE are strongly associated with positive outcomes, but the enrollment outcomes are not the same for both programs. DE students are more likely than AP students to go to college after high school, but they are less likely to first enroll in a four-year college."
"In addition, the effect of DE is driven by courses taken at the local community college campus; there is no effect for DE courses taken at the high school."
Taken together, these results suggest a relative underrepresentation of DE students at four-year colleges. This has important implications for college admission practices that are unduly influenced by AP participation and for policies addressing factors other than academic readiness that affect DE students’ ability-college undermatch.
While DE participation is associated with positive outcomes, this effect is seen only for students who took DE courses at the community college; DE participation had no effect for students who took courses at the high school. In light of current concerns about high schools’ ability to deliver college-level instruction and the lack of a standardized curriculum in DE courses, the results might call for increased quality control for DE college credits earned at high school campuses.