But according to the Harvard Joint Center for Housing Studies’ annual State of the Nation’s Housing report, released Thursday, sprawl is poised to make a comeback. According to Census data examined by JCHS, the household growth in the 2000s was mostly concentrated outside of cities – city cores only accounted for 21% of growth, compared with 38% in the suburbs and 41% in the exurbs. This was largely driven by prices, a trend that is likely to continue. The current pause in exurban housing development has more to do with cooling demand caused by the downturn than with a major change in lifestyle choices, the Harvard center says.