This article addresses the question of why certain epistemic verbs, particularly (I) think, have very high rates of zero complementizer in their clausal complements. I consider and reject the influential proposal from Thompson & Mulac (1991b) that the occurrence of zero complementizer in these contexts is associated with syntactic reanalysis of the epistemic verb and its subject to an adverbial-like epistemic phrase. Instead, I propose that zero complementizer signals a shift in the informational structure of the utterance, in which the embedded clause conveys the main assertion, but the syntactic structure of the sentence need not be altered. Further routinization is evident with I think but not with other epistemic verbs. Results from a study of newspaper prose are presented in support of the analysis.