Frequencies for first 10,000 rows of typepay variable in nhamcsed1996 dataset :

         type of payment for this visit |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
No answer, both parts a and b were blan |        267        2.67        2.67
              Preferred Provider Option |        647        6.47        9.14
               Insured, fee-for-service |      3,570       35.70       44.84
                      HMO/Other prepaid |      2,452       24.52       69.36
                               Self-pay |      1,835       18.35       87.71
                              No charge |         74        0.74       88.45
                                  Other |        298        2.98       91.43
Type of payment unspec, but insurance c |        857        8.57      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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