I think you want to use a beta regression. I don't know if it exists
(I've never tried to find it in Stata). It's similar to the
logit/probit approach, in that it transforms the data, and then
estimates the parameters using ML.
There was a paper by Smithson in Psychological Methods on this
recently - the abstract is here:
http://content.apa.org/journals/met/11/1/54
Jeremy
Come to think of it, I believe Maarten Buis said something about this
not too long ago. I assume he must sleep some time, so I'll post the
link to his page:
