ApolloChoiceModelling forum

Dear Concern,

I want to calculate the WTP from the MNL model. This MNL model is the base model. Going through the literature, I found out in calculating the WTP, which requires the ratio of the estimated coefficients.

I have looked into the example of MNL model with SP covariates. I have not included any SP covariates, the base model only contains the attributes of the alternatives which shows that they are highly significant.

If I use the delta method for calculating the WTP, I just simply used the following script:

deltaMethod_settings=list(expression=c(WTP="-b_cpeed/b_cost",
WTP_Charging_time_min="-1*(b_cpeed/b_cost)","asc_3"))
apollo_deltaMethod(model_WTP, deltaMethod_settings)


Here, bcpeed= Charging Time or Speed (which is a positive estimate), b_cost is the Charging cost (which is a negative estimate)

I have multiplied with -1 term, in order to have a positive value. The delta method settings require a 3rd argument, which was not fixed in estimation.
I just simply used asc_3.

I would like to know, is this an appropriate approach or I am leading to some fatal error?

Hi

please study the manual and help file.

The vector given in expression can have as many expressions as you want to calculate values for. So you don't need to include asc_3
should be fine