What if the model is like following: pr( xb+u<0)=pr(outcome=1) pr(0<xb+u<cut2)=pro(outcome=2) pr(cut2<xb+u<cu3)=Pr(outcome=3) ...etc the -xb- here does not include "constant" term. But, the 1st cut point(cut1)==0 here. I am thinking to use a constrained ologit (or oprobit) model. However, from the description of command, -constraint-, I can not find any setup for constrains with ologit or oprobit. Can anybody help me this? thank you very much and have a nice day Jitian * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/