In this paper, a rational choice model of the dynamics of public attention to politically relevant issues is proposed, responding to the following research questions: When and why does public attention arise in the first place? Do 'issue attention cycles' really exist? What issues are likely to attain which degree of public attention? How can public attention be measured soundly? In which way does public attention influence regulatory action, and how, in turn, is public attention affected by political action? To this end, the paper sets off with a discussion of the concepts of 'public', 'issue', 'attention' and 'cycle'. Key variables of the causal model include the acuteness/severity and accessibility/visibility of the issue at stake, as well as the ability to 'solve' the underlying problem. In an empirical study, several environmental issues and their corresponding regulation in Germany are examined in order to test the theoretical conjectures which could, for the most part, be empirically supported.