Semantic predictability of implicit causality can affect referential form choice.

Models of language comprehension show that predictable elements are easier to understand. Does predictability also guide production? While many models suggest it does (e.g., Arnold, 1998; Aylett & Turk, 2004; Levy & Jaeger, 2007; Jurafsky, Bell, Gregory, & Raymond, 2001; Mahowald, Fedorenko, Piantadosi, & Gibson; Orita, Vornov, Feldman & Daumé, 2015; Tily & Piantadosi, 2009), several models suggest that it does not make speakers more likely to select pronouns (Fukumura & van Gompel, 2010; Kehler et al., 2008; Kehler & Rohde, 2013; Kehler & Rohde, 2019; Stevenson et al., 1994). Claims that predictability does not affect pronoun production are based on evidence that certain semantic roles are more likely to be re-mentioned in discourse, but speakers do not prefer pronouns for those event roles, especially when predictability stems from implicit causality estimates. These findings contrast with studies of transfer verbs, where goals are more predictable than sources, and speakers do use pronouns more for goals versus sources (Arnold, 2001; Rosa & Arnold, 2017). Our study takes a closer look at the predictability of implicit causes, using a novel experimental paradigm that is more contextualized than the methods used in previous studies. In two experiments, we find that implicit causality does affect pronominalization. This suggests that predictability may play a broad role in both reference production and language production more generally.