I was wondering what procedure I could use in SAS to analyze a dependent variable that has many zeros, if at the same time I want to use fixed effects or clustering in the regression equation. The fixed effects or clustering does not allow one to use Tobit. I saw a reference to symmetrically trimmed least squares for this situation (Honore, Econometrica 1992). Any ideas how I could do this or an alternative estimation for this problem? I am actually thinking of using proc lifereg to estimate a Tobit model with dummy variables to capture fixed effects, but am not sure if this would work.