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. We check the forum at least twice a week. It may thus take a couple of days for your post to appear and before we reply. There is no need to submit the post multiple times.

Search found 11 matches

Go to advanced search

by dce.farmers
13 Jul 2026, 16:41
Forum: Post-estimation analysis/use of results
Topic: Sample size / power analysis for latent class analysis based on a DCE — unknown number of classes
Replies: 1
Views: 2149

Sample size / power analysis for latent class analysis based on a DCE — unknown number of classes

I'm planning a discrete choice experiment (DCE) and intend to analyze the data using latent class analysis (LCA). My design has 4 attributes, 10 choice sets, and 3 alternatives per choice set (2 substantive alternatives + a no-change/opt-out option).
I ran a pilot survey with 20 participants and ...
by dce.farmers
13 Aug 2025, 15:11
Forum: Estimation results
Topic: Individual-level of WTP
Replies: 1
Views: 31993

Individual-level of WTP

Hi,

I would like to know how I obtain the WTP at the individual-level after estimating a MNL in utility space and/or WTP-space?

Here is my code below (in WTP space).

Thanks a lot in advance!

# ################################################################# #
#### LOAD LIBRARY AND DEFINE ...
by dce.farmers
27 Oct 2024, 15:44
Forum: Model specification
Topic: Outside good or not for my MCDEV?
Replies: 9
Views: 49730

Re: Outside good or not for my MCDEV?

Thank you Stephane!

I did try to use apollo_combineModels to combine them but I am running into erros. Could you please help me with this? :mrgreen: Thank you!

This is the error I get:
combinedModels <- apollo_combineModels(list(P1 = apollo_probabilities1, P2 = apollo_probabilities2), apollo ...
by dce.farmers
25 Oct 2024, 13:23
Forum: Errors during model validation and/or estimation.
Topic: MMNL model starting value cost variable
Replies: 11
Views: 282835

Re: MMNL model starting value cost variable

Hi Stephane,

Actually, regarding your last reply, I am confused whether I should define what I find as WTP or WTA. My guess is that I have both because I have both positive and negative signs for my attributes coefficients.

Below on the picture, how I summarized my results, it is a WTA when the ...
by dce.farmers
14 Oct 2024, 16:33
Forum: Model specification
Topic: What distributions for the coefficients? Mixed Logit
Replies: 1
Views: 22358

What distributions for the coefficients? Mixed Logit

Hi,

I am estimating a Mixed Logit model and I have questions about the right distributions of the parameters I should use/test for, especially for my interaction terms. This is in the context of material/labour sharing among farmers for adoption of a new technology.

Here are my attribute and ...
by dce.farmers
20 Sep 2024, 16:47
Forum: Errors during model validation and/or estimation.
Topic: MMNL model starting value cost variable
Replies: 11
Views: 282835

Re: MMNL model starting value cost variable

Thank you Stephane! It worked by setting the starting value of my cost attribute to -7!

I have a question regarding the sign of my cost coefficients.

Here are the results I get:

Model name : MMNL_uncorrelated
Model description : Mixed logit model WITH sobol draws and cost attribute as log ...
by dce.farmers
16 Sep 2024, 13:51
Forum: Model specification
Topic: Outside good or not for my MCDEV?
Replies: 9
Views: 49730

Re: Outside good or not for my MCDEV?

Thank you so much Stephane.

I have therefore estimated a FMNL for the share allocated to A vs. status quo (alt3) and then seperately again a FMNL for the share allocated to B vs. status quo by having two separated codes (see code below, the other one is exactly the same but by replacing alt1 by ...
by dce.farmers
16 Sep 2024, 11:26
Forum: Errors during model validation and/or estimation.
Topic: MMNL model starting value cost variable
Replies: 11
Views: 282835

MMNL model starting value cost variable

Dear apollo users,

I am getting this error code in apollo when estimating a MMNL model, assuming here that the parameter of my cost attibute is distributed as lognormal and the rest of my parameters are distributed as normal.

Erreur dans apollo_mnl(c(mnl_settings, componentName2 = "model ...
by dce.farmers
08 Sep 2024, 11:33
Forum: Model specification
Topic: Outside good or not for my MCDEV?
Replies: 9
Views: 49730

Re: Outside good or not for my MCDEV?

Yes of course.

I am attaching a screenshot of a choice card below. The status quo has specific levels of attributes and we also made it clear to farmers that they would not plant any resistant varieties by choosing the status quo. For each choice card , farmers were asked the following question ...
by dce.farmers
05 Sep 2024, 10:12
Forum: Model specification
Topic: Outside good or not for my MCDEV?
Replies: 9
Views: 49730

Re: Outside good or not for my MCDEV?

Dear Stephane,

Thank you for your answer. The fmnl model looks interesting but I am not sure if I can use it in my case for the following reasons:

- farmers were not asked to indicate the share of land they would allocate to the status quo (alternative 3) in case they selected it. I could however ...

Go to advanced search