Hi everyone,

I'm working on a project about internet lending which focuses on the relationship between default risk of borrowers and the interest rate. There are about 30,000 lending samples in the dataset. And I've built a heckprobit model to fix the sample selection bias since only in successful lending samples can whether there is a default be observed. My model goes on as below:

first step:
success= rate+X1+X2+X3
second step:
default=rate+Z1+Z2+Z3

The variable default is a binary one representing whether the borrower defaults or not (=1, default; =0, no default) . success represents whether the lending is successful (=1, succeed; =0, fail). rate represents the interest rate. Others are control variables including both continuous and categorical ones.

My problem is when I ran the model in Stata, there was no output. I'd love to ask the possible reasons that can lead to this.

Thank you,
Yubo Fu