Celia Patricia Vera <[email protected]>:
You want to compare densities of variable pscore for two populations
defined by treatment==1 and treatment==0. This can be done with
-dotplot- or -tw hist- if many observations have the same value (as
frequently happens when using a number of categorical values in PS
matching), e.g.
sysuse auto, clear
dotplot mpg, over(for)
(taking mpg as pscore and for as treatment) but a more general
approach is to use -kdensity- or -kdens- (avail via -ssc inst kdens-)
like so:
g x=_n-1+floor(r(min))
replace x=. if x>ceil(r(max))
kdens mpg if for==0, at(x) gen(t0) nogr
kdens mpg if for==1, at(x) gen(t1) nogr
line t0 t1 x, leg(lab(1 "Untreated") lab(2 "Treated"))
where there are a host of options for -kdens- that may change your results, e.g.
kdens mpg if for==0, at(x) gen(u0) nogr bw(o) k(t)
kdens mpg if for==1, at(x) gen(u1) nogr bw(o) k(t)
line t0 u0 t1 u1 x
On 6/28/07, Celia Patricia Vera <[email protected]> wrote:
I want to graph the density function for the
propensity score for both treated and no treated (in
the same graph) in order to see the overlapping
regions.
I do not find the way to do that.
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