Linguistic Drift?

[Ellen L. Contini-Morava]

About predicting the direction of language change:  work of Labov
and others on changes in progress are evidently also
predictions of future developments (see, for example, "The
intersection of sex and social class in the course of linguistic
change", in Language Variation & Change 2, 1990;  "The social
origins of sound change", in W. Labov [ed], Locating Language in
Time and Space and many others.)  A change in progress is identified
by comparing the speech of older and younger members of a speech
community, so I don't know if this would count as a "prediction"
exactly, if by that is meant predicting a change that hasn't started
yet.  But in cases where chain-shifting of vowels is occurring, for
example, one might be able to predict a "drift" in this direction even
when a particular change hasn't occurred yet.

With regard to the role of social attitudes in reducing
gender bias in American English, some changes (such as the
decreasing use of suffixes like -ess [authoress, poetess
etc.], the decreasing use of generic he, gender-neutrautral occupation
terminology [server, flight attendant, letter carrier etc.]) seem to
be already in progress, and this could be demonstrated by comparing
contemporary English with that of a couple of generations ago.  It may
be limited (for now, anyway) to certain registers, especially written
ones, and I don't know of references that make predictions
specifically about this.

Ellen Contini-Morava