Important: Read this before posting to this forum

  1. This forum is for questions related to the use of Apollo. We will answer some general choice modelling questions too, where appropriate, and time permitting. We cannot answer questions about how to estimate choice models with other software packages.
  2. There is a very detailed manual for Apollo available at http://www.ApolloChoiceModelling.com/manual.html. This contains detailed descriptions of the various Apollo functions, and numerous examples are available at http://www.ApolloChoiceModelling.com/examples.html. In addition, help files are available for all functions, using e.g. ?apollo_mnl
  3. Before asking a question on the forum, users are kindly requested to follow these steps:
    1. Check that the same issue has not already been addressed in the forum - there is a search tool.
    2. Ensure that the correct syntax has been used. For any function, detailed instructions are available directly in Apollo, e.g. by using ?apollo_mnl for apollo_mnl
    3. Check the frequently asked questions section on the Apollo website, which discusses some common issues/failures. Please see http://www.apollochoicemodelling.com/faq.html
    4. Make sure that R is using the latest official release of Apollo.
  4. If the above steps do not resolve the issue, then users should follow these steps when posting a question:
    1. provide full details on the issue, including the entire code and output, including any error messages
    2. posts will not immediately appear on the forum, but will be checked by a moderator first. This may take a day or two at busy times. There is no need to submit the post multiple times.

Search found 1002 matches

by stephanehess
01 May 2024, 11:39
Forum: Model specification
Topic: MNL for Case 1 BWS: saddle point convergence
Replies: 1
Views: 21

Re: MNL for Case 1 BWS: saddle point convergence

Jay

can you show us the output, please?

Thanks

Stephane
by stephanehess
01 May 2024, 11:37
Forum: Data preparation, processing and pre-estimation analysis
Topic: Handling 'Not Available' Data
Replies: 1
Views: 14

Re: Handling 'Not Available' Data

Hi I would in your case recommend option 1. Even when I treat income as a continuous variable in my models, I do not exclude people with missing data, nor do I assign them to another category. Rather, I estimate a different parameter for them, which would be in line with your idea to treat it as cat...
by stephanehess
01 May 2024, 11:35
Forum: Model specification
Topic: latent class model
Replies: 4
Views: 2750

Re: latent class model

Hi I don't have any such example files, but like I said, this would all be accommodated by moving the apollo_panelProd call to be after apollo_lc. It's a very simply change for you to make For the class allocation model, you could then include covariates that vary across observations in the class al...
by stephanehess
30 Apr 2024, 14:03
Forum: Model specification
Topic: Order of parameters in apollo_beta (LC model)
Replies: 1
Views: 20

Re: Order of parameters in apollo_beta (LC model)

Paul

the order does not matter as they are indexed by name. So there must be another issue.

Did you compare the starting LL?

As an aside, I strongly suggesting using different starting values in the different classes

Stephane
by stephanehess
24 Apr 2024, 15:35
Forum: Estimation results
Topic: Low t-ratios in MNL
Replies: 1
Views: 79

Re: Low t-ratios in MNL

Hi

there could be many reasons for this. Either there really is no effect (in which case that is a finding), or you don't have enough data, or a bad design. But this is a general question, not Apollo related

Stephane
by stephanehess
24 Apr 2024, 15:33
Forum: Data preparation, processing and pre-estimation analysis
Topic: deal with Missing data
Replies: 1
Views: 73

Re: deal with Missing data

Hi

you can either impute them, or estimate a separate effect for those people

Stephane
by stephanehess
24 Apr 2024, 15:31
Forum: Post-estimation analysis/use of results
Topic: Marginal rate of substitution for different sociodemographic groups
Replies: 3
Views: 308

Re: Marginal rate of substitution for different sociodemographic groups

Hi

your unconditional distributions will not be different for people with different socio-demographics unless you have included the interactions in apollo_randCoeff. So subsetting the data will not do anything

Stephane
by stephanehess
24 Apr 2024, 15:29
Forum: Post-estimation analysis/use of results
Topic: WTP for mixed logit with random parameters
Replies: 24
Views: 34958

Re: WTP for mixed logit with random parameters

Hi the delta method in Apollo is for individual model parameters, not for distributed coefficients. In your case, you would need to use apollo_unconditionals to obtain the draws for the coefficients and calculate WTP moments that way, but you would not be able to use apollo_deltaMethod as you cannot...
by stephanehess
24 Apr 2024, 15:27
Forum: Errors during model validation and/or estimation.
Topic: error in getiing Standarad error of e mdcev model
Replies: 3
Views: 107

Re: error in getiing Standarad error of e mdcev model

Hi

it's not clear what you mean exactly. Do you want to interact this with covariates?

Stephane