In message , at 16:36:06 on Sun, 22
Jan 2017, Neil Williams remarked:

Without some bureaucracy, how do you tell the purpose of the visit?

Like Switzerland, which is in Schengen but does not allow freedom of
work without a work permit (though these are available in large numbers
to EU people), you control the work, not the entry.

My question was about the USA who *do* control the entry (as well as the
work).
--
Roland Perry