Astin, A. W., Sax, L. J., & Avalos, J. (1999). The Long-Term Effects of Volunteerism During the Undergraduate Years. THE REVIEW OF HIGHER EDUCATION, 21 (2): 187-202.

This study addresses the question of whether effects of volunteer service during the undergraduate years persist once students leave college. Data are drawn from 12,376 students attending 209 institutions who were followed up four and nine years after college entry. Results show that even when pre-college service participation is controlled, student participation in volunteer service during the undergraduate years is positively associated with a variety of cognitive and affective outcomes measured nine years after entering college.