Dear all,

I am writing here today with the hope that someone might be able to help me with an obstacle that I am facing on Stata. I am trying to run the following non-linear regression:

nl (price = log(1-exp(-1*{a1}*Tau))+{a2}) where price is the dependent variable and Tau is the regressor.

On running this regression, I am continuously getting this error: "starting values invalid or some RHS variables have missing values".

Now I am completely stuck at this point and don't really know what to do. My RHS variables do not have any missing values and I have tried many different initial values for Tau but always get the same error.

Please let me know if anyone has any suggestions on what I should do.

Thanks
Best,
Prateek