Frequencies for first 10,000 rows of typepay variable in nhamcsopd1995 dataset :

     expected type of payment for visit |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
No answer, both parts A and B were blan |        192        1.92        1.92
              Preferred Provider Option |        543        5.43        7.35
               Insured, fee-for-service |      4,720       47.20       54.55
                      HMO/Other prepaid |      1,771       17.71       72.26
                               Self-pay |      1,147       11.47       83.73
                              No charge |        200        2.00       85.73
                                  Other |        293        2.93       88.66
Type of payment unspec, but insurance c |      1,134       11.34      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016