Summary statistics for sf12000zcta5distance500miles dataset :

by Jean Roth , jroth@nber.org , 4 Jan 2016

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
        zip1 |          0
        zip2 |          0
 mi_to_zcta5 |512,722,310    468.9303    204.8338   .0329837    804.672

by Jean Roth , jroth@nber.org , 4 Jan 2016