This paper proposes a different methodological approach to understanding the determinants of survey participation. Data was collected by means of a Web panel survey conducted with a population of university students (N = 330). First, we focused on theory-driven measures of consequences of participation: costs of participating, survey situation, generalized attitudes about surveys, and past survey-taking behaviours using a paper-and-pencil questionnaire. A subset of this sample was subsequently invited, twice, to participate in a Web panel survey. This comparison allows the theory-driven prediction of unit non-response. We found that time resources and costs (fear of data misuse) are the primary determinants of participation in the first wave; and salience of topic and costs (burdensome survey experience in the first wave) are the major predictors of participation in the second wave. These results support the theory of rational action to explain unit non-response and match well with the existing empirical evidence.