In the spring, invitations to participate were sent to a total of 3924 students. This represented 1964 invitations to participants who had completed the fall survey (note that a small number of students were no longer at the university; we are just beginning to initiate procedures to follow-up individuals who have left the university). Eighty percentage of those individuals completed the follow-up survey (N = 1562), 94% of whom picked up their payment. There were small demographic differences associated with attrition, with males (χ 2 = 14.20, p < 0.01) and white participants (χ 2 = 6.04, p = 0.05) being somewhat less likely to complete the spring follow-up. However, importantly, we did not observe any differences in terms of parental alcohol problems [χ 2(1) = 0.03, p = 0.87]; high school conduct problems [B(2020) = 0.04, p = 0.80]; extraversion [B(2041) = −0.16, p = 0.62]; baseline peer deviance [B(2015) = −0.75, p = 0.08]; alcohol frequency [B(1729) = −0.23, p = 0.34]; alcohol quantity [B(1690) = 0.02, p = 0.94]; alcohol problems [B(1980) = −0.01, p = 0.90];
