I have installed DCchoice, Icens and aods3 packages and using them in calculating Willing To Pay from samples.
And I typed codes as follows ;
model2 <- asw1 + asw2 ~ 1 | log(bid1) + log(bid2)
model2_result <- dbchoice(model2, data = cvm_data, dist = "log-logistic")
Then an error message came as follows ;
Error in optim(ini, fn = dbLL, method = "BFGS", hessian = TRUE, dvar = yvar, : initial value in 'vmmin' is not finite
I do not know what the cause of this error message is and how can I solve this problem.