If we were to decide that local homogeneity of values is something we wanted to encourage -- which I'm not sure of -- a subsidy for moving costs would probably help, but I don't think it's sufficient to overcome the inertia that keeps e.g. Texans with Californian values in Texas. People have lots of ties to a place besides the purely financial: moving implies leaving friends and often family, finding a new job and new housing, probably learning a certain amount of new cultural content, etc.