Does anyone know the answer to this or where to find it?
I don't understand the question.
I'm sorry, goofy me, of course it's clear in my little head. What I mean is, do most buyers come from the same region or local area as the house they buy? Or are they coming in from out of state or across the country?
That depends on where you are. In this area, there are some buyers coming from out of state to retire. Your area is probably different, but I suspect there are very few places where the majority of buyers are other than local. Only your local real estate people would know.
It also depends on what niche market your home is in. Some niche markets appeal to retirees and many of those may come from out of area. Hobby farming is another niche market where you may get people from out of area. Housing near military bases is another example of buyers being from out of the area.
Also housing near major employeers known for transferring employees frequently such as IBM in Poughkeepsie.
We have a large military presence here which increases by the thousands every year, including dependents.
For other movements, check with moving companies or rental companies, they keep track of the state to state movements of their vans.
Good answers above... The answer to your question is regional.
Here in Charlotte, NC, 85% of my business last year was from either the upper NE, or from Florida. (also known as halfbackers)