How did you learn that he would like to transfer?
Anyways, if I were you, I won't count on keeping him by impressing him.
First, you may not be able to impress him. Second, he may not be
impressed
no matter what you do. Say, he wants to transfer simply because he hates
where your school is, or he has a 2-body problem, etc.
I would ask him directly but of course politely. If he says he will
transfer
should there be an opportunity, I will certainly consider revoking RA
offer
. New faculty cannot afford wasting precious RA money on a student that
is
coming to you for the sole purpose of transferring to another place. It
is
very difficult for a 1st-year student to deliver anything. He will be
swamped with coursework. Even if he will be on a TAship or fellowship, I
would consider revoking the offer, because TAship/fellowship is also
precious
departmental resource and you could make that investment on someone that
will stay and deliver results later.
Don't count on impressing him and don't count on a first-year student to
deliver anything.
But if you still decide to work with him, my suggestion is to give him
some
topic that is well-defined, with methods figured out by yourself
already,
and that only needs execution from a student. And that topic shouldn't
be on
the critical paths of your overall project.
