What do we know about the language extinction rate?

Does one language really disappear every two weeks? The statistic is widely cited in discussions of language endangerment, yet its empirical basis remains unclear. This article traces the origins of the claim and reviews the evidence on which it rests. We first revisit the conjecture that half of the world's languages were already no longer transmitted to the next generation in the early 1990s and examine how this assumption gave rise to the "one language every two weeks" figure. Using assessments from major linguistic catalogues, including the UNESCO Atlas and Ethnologue, we show that the proportion of languages no longer transmitted to younger generations is substantially lower than originally assumed. We then review more recent attempts to estimate the rate of language extinction from documented disappearances, rather than from current intergenerational transmission statuses. These studies suggest a much lower rate of roughly one language every six to thirteen weeks but rely on methods that are subject to important - yet difficult to quantify - sources of bias. We conclude that the widely cited claim that one language disappears every two weeks is probably too high, while the accuracy of more recent estimates cannot presently be determined. Drawing on approaches developed in biological extinction research, we conclude by outlining how methods that account for the population at risk, supported by data documenting the demographic trajectories of the world's languages, could enable more robust estimates of the current rate of language extinction.