The extent to which credit-based transition programs are successful in reducing barriers to college depends upon the features of each program and the students they serve. In these ways, AP and dual credit tend to differ, and are thus often regarded as distinct curricular acceleration strategies with the potential to differentially benefit particular groups of students (Karp, 2015; An, 2013;
Speroni, 2011a). Administered nationally by the College Board, AP courses are taught by high school teachers who are specially trained to deliver standardized curriculum in a particular course intended to be college-level in intensity. In order to receive college credit, an AP student must take the optional exam at the end of the course and receive a passing score, which is typically a 3 or above out of 5 points maximum (Smith, Hurwitz, & Avery, 2017). Even so, the minimum score required for college credit varies by AP exam subject and by the postsecondary institution accepting credit. Historically, AP enrollment and test participation rates have been low among minority and low-SES students (Klopfenstein, 2003), and so to address this criticism, the College Board has worked to waive exam fees and encourage schools to expand access to AP course opportunities for
underrepresented students (College Board, 2014). Between 2003 and 2013 the number of students who took an AP exam roughly doubled, from 514,000 to over 1 million.
In comparison to the standardized nature of AP, dual credit programs vary widely in their course curricula, structure, and college credit criteria across – and even within – states, depending on the local preferences and objectives of stakeholders (Karp et al., 2007; Borden et al., 2013; Taylor, Borden, & Park, 2015). Courses range from being college-preparatory in nature to focusing more on vocational skills or CTE topics. At the same time, policies outlining the scope of dual credit
programs and procedures for how college credit may be earned and transferred vary. This variation may accommodate the history or strengths of localities and encourage innovation. However, this non-conformity also raises concerns about course quality assurance and hampers efforts to
systematically study the effectiveness of dual credit programs in encouraging high school and college success.3
Though national demographic figures on participants are unavailable (Allen, 2010), earlier studies suggest white and affluent students are more likely to enroll in these courses (Museus, Lutovsky, & Colbeck, 2007). However, especially in recent years, dual credit has been touted as a vital policy approach that can successfully target students underrepresented in college due to these programs’ flexibility; and many states have used this aim to justify broadening dual credit coverage and course offerings in order to engage students across the geographic, socioeconomic, and even academic achievement spectrum (Karp et al., 2007; Hoffman, Vargas, & Santos, 2009; Hughes et al., 2012). Tennessee’s statewide dual credit initiative, the focus of this paper, was established for many of these reasons.
When it comes to the credit-bearing dimension of dual credit courses, no studies have investigated the causal effect of receiving college credit in high school through dual credit. However, two papers have examined the effect of receiving college credit through scoring a higher AP score while in high school. Using data from the College Board and the National Student Clearinghouse for graduating high school cohorts 2004-2009, Smith, Hurwitz, and Avery (2017) implement an RD approach to estimate the effect of earning a higher AP integer score (1-5), and thus college credit, on college completion.4 They find that students who receive college credit on a single AP exam are 1-2
percentage points more likely to receive a BA degree within four years of high school graduation compared to their peers who do not receive college credit. Though receipt of college credit has no
3 Concerned about issues of quality assurance, the National Alliance of Concurrent Enrollment Partnership (NACEP) serves as national voluntary accreditation organization for dual credit and dual enrollment programs and courses based on a set of established criteria. For more information, see http://www.nacep.org/about-nacep/.
4 They have access to the underlying AP exam continuous raw scores that map into the 1-5 integer scaled scores. They use these underlying continuous scores to compare students right around each scoring threshold (1/2, 2/3, etc.).
effect on the six-year graduation rate, suggesting that earning college credit in high school improves time-to-degree, though not overall completion. Looking at other integer margins where scoring above or below a threshold does not distinguish earning college credit, they do not find an effect on four-year BA completion. Therefore, they attribute the increased propensity to graduate within four years to AP college credits’ direct ability to fulfill college graduation requirements (e.g., introductory course requirements, general education requirements) and not just the psychological benefits of earning a higher integer score.
In a related paper that employs the same data source, student cohorts, and RD technique, Avery, Gurantz, Hurwitz, and Smith (2018) estimate the effect of receiving a higher AP integer score on college major choice. They find that scoring a higher AP integer score increases the probability of a student decides to major in that exam subject, with the effects strongest at the 4/5 margin.
Compared to their similarly scoring peers who merit a 4, students scoring a 5 are 0.64 percentage points (or 5 percent) more likely to major in the AP exam’s subject area. Avery et al. also find a similar positive relationship at the 2/3 margins and 3/4 margins, though they are smaller in magnitude. Interestingly, whereas the results from their paper looking at BA attainment found the effect of earning college credits on completion was due to AP credits’ ability to meet college course requirements, they find evidence that the positive effect of AP score on college major choice is primarily driven by a behavioral effect. A higher integer scores communicates a positive signal to students, shifting their major choice, even at integer margins where a higher score does not coincide with a boost in college credits.5 The credit-bearing aspect, on other words, does not seem to matter
in driving student major decisions.
5The most common threshold that coincides with a jump in college credits is at the margin of earning a 2 or a 3 on an
The findings from these two AP papers suggests that the overall effect of earning college credit in high school may affect some aspects of students’ postsecondary course-taking behaviors and performance, but not others. While it may mechanically reduce a student’s time-to-degree by helping them meet degree requirements earlier, it may not necessarily influence their course-taking behavior. These papers also highlight the importance of considering the signaling effect of attaining a certain score on an exam with college-credit-bearing potential – whether the student earns college credit with their score or not.
This paper adds to the existing body of literature by providing insight into how dual credit, as opposed to dual enrollment or AP, affects postsecondary enrollment and performance through the mechanism of college credit accrual. I rely on unique data from Tennessee’s statewide dual credit initiative to estimate the causal effect of successfully obtaining college credit on a range of early postsecondary outcomes including college choice, GPA, credits accrued, and persistence. Using an RD approach, I explore how outcomes differ between dual credit participants who obtain college credit and those participants whose course performances do not merit college credit.