My logistic model's dependent variable is cost/benefit ratio of an investment. It takes value ''1'' if c/b ratio>=1 and ''0'' if ratio<1. independents are REGION (takes value ''1'' if investment includes one region, and ''0'' if two or more regions), TYPE (''1'' if its new investment and ''0'' otherwise) SECTOR (manufacturing, agriculture and serving -serving is base category). responses (1) if an investment’s cost/benefit ratio≥1 and (0) if c/b ratio<1.

When constant term included, the model cannot be estimated because of endless iterations saying ''no convergence'' When constant excluded, all parameters are significant at %5 and %10, prob>chi2=0.0082 wald(4)=13.74.

It’s clear that constant term is not good for my model. As far as i understand, cost/benefit ratio may not exist under the assumption all independents equal to zero. But how can i run this model in STATA? how could i interpret the coefficients and Which statistics or goodness of fit measure should i use for evaluating the significance of model the model without constant term? And what happens to logit model without constant (respect to the convergence error)?

Thanks for now. ]]>