Still No Evidence for an Effect of the Proportion of Non-Native Speakers on Natural Language Complexity

In a recent study published in this journal (https://doi.org/10.1098/rsos.181274), I demonstrated that large numbers of L2 (second language) speakers do not appear to affect the morphological or information-theoretic complexity of a language. This update paper has three primary aims: First, I rebut the critique recently raised by Kauhanen, Einhaus, and Walkden (https://doi.org/10.1093/jole/lzad005). While I acknowledge the value of post-publication commentary on published research, I show that the points of criticism they raise were already explicitly addressed and analysed in my original paper. Furthermore, I demonstrate that the alternative analyses they propose do not hold up under closer scrutiny. Second, I introduce new data on the information-theoretic complexity of languages, with estimates derived from various language models—ranging from simple statistical models to advanced neural networks—based on a database of 40 multilingual text collections comprising a wide variety of text types. Third, I re-analyse the information-theoretic and morphological complexity data using novel methods that better account for model uncertainty in parameter estimation, as well as the genealogical relatedness and geographic proximity of languages. Consistent with my earlier findings, the results do not provide evidence for an effect of the presence of large numbers of L2 speakers on complexity across languages.