As W. Labov has passed away, I came across a comment reposting this screenshotted request, along with the paper in question:
https://betsysneller.github.io/pdfs/Labov1966-Rabbit.pdf
The paper is quite a rollercoaster, ranging from describing of disturbingly racist ideas about native Hawaiian and Black children that some scientists still pushed at the time (1970!*), to Labov's own disarmingly cute and humane solution to the issue of testing children's language abilities.
Edit: *1970 - according to the article itself, which is apparently based on Labov's 1970 talk; however, the URL suggests that the article was published in 1966, which is contradictory. I'll try to find out where and when this was actually published...
Edit 2: It looks like it is from 1970, from Working Papers in Communication, vol. 1 (Honolulu: Pacific Speech Association). It is surprising that a recently published book also claims that it's from 1966, probably the authors got the file from the same URL with the wrong year.
Edit 3: The original Twitter thread: https://xcancel.com/betsysneller/status/1516848959284678656
> a fun anecdote is that Labov didn't correct people on the pronunciation of his last name (/lə'bʌv/ or /lə'boʊv/) because he liked to observe the variation.
man probably kept running averages in his head. you come in, he considers your age, class, subculture and diet and is able to predict how you'll call him
Everybody is posting these elaborate eulogies and Peter Trudgill just says
> We owe him everything.
which I imagine must sound pretty trite to the casual onlooker, but if you've read both Labov and Trudgill you kinda feel the weight of this.