  In a recent paper published in the Journal of Language Evolution, Kauhanen,
Einhaus & Walkden (https://doi.org/10.1093/jole/lzad005, KEW) challenge the
results presented in one of my papers (Koplenig, Royal Society Open Science, 6,
181274 (2019), https://doi.org/10.1098/rsos.181274), in which I tried to show
through a series of statistical analyses that large numbers of L2 (second
language) speakers do not seem to affect the (grammatical or statistical)
complexity of a language. To this end, I focus on the way in which the
Ethnologue assesses language status: a language is characterised as vehicular
if, in addition to being used by L1 (first language) speakers, it should also
have a significant number of L2 users. KEW criticise both the use of
vehicularity as a (binary) indicator of whether a language has a significant
number of L2 users and the idea of imputing a zero proportion of L2 speakers to
non-vehicular languages whenever a direct estimate of that proportion is
unavailable. While I recognise the importance of post-publication commentary on
published research, I show in this rejoinder that both points of criticism are
explicitly mentioned and analysed in my paper. In addition, I also comment on
other points raised by KEW and demonstrate that both alternative analyses
offered by KEW do not stand up to closer scrutiny.

Computation and Language;Applications