# st: Calculating area under a curve

 From Padmakumar Sivadasan To statalist@hsphsun2.harvard.edu Subject st: Calculating area under a curve Date Fri, 27 Nov 2009 08:22:33 -0600

```Dear All,

I am analyzing the performance of companies indicated by a variable
v1. Variable v1 has a range 0-10 where higher values indicate poorer
performance.  I am attempting to compare the performance of companies
for the country as a whole and to that at the local level
(Metropolitan Statistical Area). I am interested not only in the mean
value of v1 but also the variability of v1. One suggestion I got was
to compute the cumulative probabilities at the national and local
levels and then compare the area under the cumulative probability
distributions at the local level to that at the national level.

I understand that I can use the –cumul- function in Stata to calculate
the cumulative probabilities but I couldn’t find a method to calculate
the area under the cumulative probability curve. I have two questions
in this regard
(1) Is there a way in Stata to calculate the area under cumulative
probability curve?
(2) Could someone point me to reference that I can use to read up on
this method?

Thanks