Many students during their college careers consider withdrawing from their respective college or university. Understanding why some students decide to withdraw yet others persist has implications for both the well being of students as well as for institutes of higher education. The present study develops a model of the decision to withdraw drawing on theories of voluntary employee turnover from organizational psychology and signal detection theory from the cognitive sciences. The model posits that precipitating events or shocks (e.g., changes in tuition) lead students to consider withdrawing from the university. If the evidence surpasses a criterion then the student decides to withdraw. The model was used to identify shocks students were sensitive to and to test hypotheses about the underlying decision process. The theoretical implications of this model in terms of understanding and predicting student withdrawal decisions and voluntary employee turnover decisions are discussed.