I too would like to see some real numbers behind this. But I will say that I took greyhounds and amtrak in / out of CA a lot growing up in the bay area and I had numerous experiences talking to homeless folks who had been put on the train or bus by law enforcement in counties outside CA for destinations including SF and San Diego. I never experienced the inverse of homeless folks getting shipped out of CA. Always stuck with me for whatever a personal anecdote is worth.