Nested Logit Model

[Alene Lucille Holmgren]

Dear Professor Bierlaire, 

I hope you are well. I am attempting to estimate three nested iterations of a previously converged MNL. The estimation report for the MNL is presented, however, this same MNL, with the same specifications, is no longer converging. My problems are two-fold: 

1. As stated, my MNL will no longer converge, despite having done so previously. 

2. My nested models have never converged - I have attempted to use different optimization algorithms and have greatly increased the maximum iterations to no avail. 

The nested models will converge if I specify a constants only model. Using NestsforNestedLogit yields the same general issues. I have attached my codebook and successful estimation below. Thank you very much in advance. 

Best wishes, 

Allie