In a recent paper published in the Journal of Language Evolution, Kauhanen,
Einhaus & Walkden (this https URL, KEW) challenge the
results presented in one of my papers (Koplenig, Royal Society Open Science, 6,
181274 (2019), this https URL), 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.

本文回应 KEW 关于非母语使用者对语言语法或统计复杂性的影响。作者在此重新强调了语言指标的使用以及非车辆语言的 L2 使用者数量等问题，并辩称 KEW 的方法不可行。