Michelle Dalmau and I conducted a survey a few years ago of those 
working in libraries to ask about their involvement with and interest in 
text encoding:

We touched on some of these questions.  If it matters what is done 
outside libraries, then this may be too narrow to be useful.

You might also be interested in the research that was part of the grant 
supporting the development of TEI Tite:

That work, however, is even older.


On 4/7/17 5:32 PM, Paul Schaffner wrote:
> Is anyone aware of a survey (or willing to provide information
> sufficient for
> me to make a survey) of those universities, departments, libraries, and
> the like
> that provide some sort of ongoing capacity to produce marked-up text?
> Whether through long-standing projects, or a long-standing service that
> survives from one project to the next? I am thinking particularly of
> TEI-based
> encoding, or at least of texts for which TEI is a reasonable solution.
> pfs