boston building boom part XXXIV

I'm noticing lots of cranes in the city these days. Their locations feel concentrated in certain areas--"fringe of the core" districts. I wonder who finds clusters more attractive--the developers or the lenders. On the whole, Boston seems to be improving, but the construction of luxury high rises means less to the ordinary citizen than a major push for infrastructure improvement would have. I would be more impressed if there was significant mid-rise, middle income development occurring in fringe districts. That type of construction is hard to organize, design, finance, and permit.