d quaids_delta2.  Utility for demand system estimation.
d Program by Brian Poi, Stata Corp <bpoi@staeta.com>.
d
d ^quaids_delta2^ computes the matrix needed to implement the delta 
d method when fitting an almost ideal demand system (AIDS).
d
d see also: Poi, B. P. (2002). "From the helpdesk: Demand system estimation." 
d Stata Journal, 2(4): 403-410.
f quaids_delta2/quaids_delta2.hlp
f quaids_delta2/quaids_delta2.ado