The abstract of the paper

Life in the Fast Lane: Effects of Early Grade Acceleration on High School and College Outcomes
by Katie Larsen McClarty
Gifted Child Quarterly January 2015 vol. 59 no.

is at http://gcq.sagepub.com/content/59/1/3.abstract . The author's email is at the site -- maybe she would email a copy if asked. Below is a summary.

Life in the Fast Lane: Effects of Early Grade Acceleration on High School and College Outcomes
Amber M. Northern, Ph.D.
February 25, 2015
Quote
A new study published in the latest issue of Gifted Education Quarterly examines the long-term impact on young students of skipping a grade (also known as acceleration) on subsequent academic outcomes. Analysts used the National Education Longitudinal Study database (NELS) to begin tracking a representative cohort of eighth-grade students in 1988, then follow them through high school and again two and eight years post-high school (i.e., through 2000). A variety of outcome data were collected, including PSAT, SAT, and ACT scores, students’ GPAs, and college aspirations—as well as college measures, such as the selectivity of the institution, GPA for each college year, and degree attainment. All students who had ever skipped at least one grade prior to eighth grade comprised the acceleration group. Thus, the sample included kids who ranged from age nine to age thirteen while in eighth grade (the mean age was 12.7). Those students were then matched with a set of older, non-accelerated, same-grade peers from NELS based on gender, race, SES, and eighth-grade achievement. The accelerated and non-accelerated groups were nearly identical on these variables.