how to: Separate a continuous variable by % proportions?

Question

I have a continuous variable (in this case, fees spent). How do I determine % spending cutoffs? i.e. how do I know what dollar amount separates the bottom 50% from the top 50% (similarly for any other % I may be interested in). Thank you very much for any help

Answer 1

First, make good use of Stata's help files: e.g., search percentiles returns a list of possible commands. Two commands that will likely be of use are summarize (with the detail option; note that you can use return list afterwards to view/store results [regardless of whether the detail option was specified]) and pctile.

See http://www.stata.com/help.cgi?summarize and http://www.stata.com/help.cgi?pctile for more information.

For example:

. sysuse auto
(1978 Automobile Data)

. summarize price, detail

                            Price
-------------------------------------------------------------
      Percentiles      Smallest
 1%         3291           3291
 5%         3748           3299
10%         3895           3667       Obs                  74
25%         4195           3748       Sum of Wgt.          74

50%       5006.5                      Mean           6165.257
                        Largest       Std. Dev.      2949.496
75%         6342          13466
90%        11385          13594       Variance        8699526
95%        13466          14500       Skewness       1.653434
99%        15906          15906       Kurtosis       4.819188

. di r(p50)
5006.5