Hi
are you able to share your code and data with me and I can look into it
Stephane
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- 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.
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Search found 1355 matches
- 16 Apr 2026, 08:34
- Forum: Errors during model validation and/or estimation.
- Topic: Error when running Mixed Logit model in Apollo
- Replies: 5
- Views: 36769
- 02 Apr 2026, 08:24
- Forum: Models and estimation
- Topic: Scenario prediction with apollo_prediction and respondent-specific BAU: shares vs max(p) vs simulation
- Replies: 3
- Views: 969
Re: Scenario prediction with apollo_prediction and respondent-specific BAU: shares vs max(p) vs simulation
Hi
you are getting different predictions in different rows given the probabilistic nature of the model, so a separate choice is sampled in each row
Stephane
you are getting different predictions in different rows given the probabilistic nature of the model, so a separate choice is sampled in each row
Stephane
- 27 Mar 2026, 08:10
- Forum: Models and estimation
- Topic: Scenario prediction with apollo_prediction and respondent-specific BAU: shares vs max(p) vs simulation
- Replies: 3
- Views: 969
Re: Scenario prediction with apollo_prediction and respondent-specific BAU: shares vs max(p) vs simulation
Hi
max(p) is always the incorrect approach as it ignores the probabilistic nature of the model. If you need predictions at the person level, you indeed need to sample according to the probabilities. Have a look at ?apollo_prediction and the simChoice setting
Re BAU, I think your approach sounds ...
max(p) is always the incorrect approach as it ignores the probabilistic nature of the model. If you need predictions at the person level, you indeed need to sample according to the probabilities. Have a look at ?apollo_prediction and the simChoice setting
Re BAU, I think your approach sounds ...
- 25 Mar 2026, 10:19
- Forum: Examples (existing and requests for new ones)
- Topic: HB: Retrieving iteration-level draws of random parameters
- Replies: 1
- Views: 636
Re: HB: Retrieving iteration-level draws of random parameters
Hi Siqi
you need
in saveOutput_settings
Have a look at
Stephane
you need
Code: Select all
saveHBiterations=TRUEHave a look at
Code: Select all
?apollo_saveOutput- 12 Mar 2026, 07:26
- Forum: Estimation results
- Topic: Unexpected sign for remuneration coefficient
- Replies: 7
- Views: 54108
Re: Unexpected sign for remuneration coefficient
Hi
it seems like this is what is happening in your data, i.e. people choose options with lower renumeration, and any constraints you impose on the model or treatment of heterogeneity will just mask this.
Stephane
it seems like this is what is happening in your data, i.e. people choose options with lower renumeration, and any constraints you impose on the model or treatment of heterogeneity will just mask this.
Stephane
- 09 Mar 2026, 18:25
- Forum: Model specification
- Topic: truncated normal for random parameters
- Replies: 1
- Views: 30915
Re: truncated normal for random parameters
Hi
truncated normal would not allow you to calculate WTP. How about log-uniform, which is an exponential of uniform. Shorter tails than Lognormal
Stephane
truncated normal would not allow you to calculate WTP. How about log-uniform, which is an exponential of uniform. Shorter tails than Lognormal
Stephane
- 09 Mar 2026, 18:24
- Forum: Model specification
- Topic: Combining experiments and feasibility of using nested logit structure
- Replies: 3
- Views: 41738
Re: Combining experiments and feasibility of using nested logit structure
Hi
your approach with alpha will work on the assumption that there is no other heterogeneity in sensitivities between the two experiments.
Re NL, the issue is that you only ever have two alternatives available at a time
Stephane
your approach with alpha will work on the assumption that there is no other heterogeneity in sensitivities between the two experiments.
Re NL, the issue is that you only ever have two alternatives available at a time
Stephane
- 22 Feb 2026, 09:14
- Forum: Models and estimation
- Topic: WTP estimates
- Replies: 1
- Views: 31100
Re: WTP estimates
Hi
how about your MNL results? Were they also unexpectedly high?
Stephane
how about your MNL results? Were they also unexpectedly high?
Stephane
- 13 Feb 2026, 10:37
- Forum: Estimation results
- Topic: Unexpected sign for remuneration coefficient
- Replies: 7
- Views: 54108
Re: Unexpected sign for remuneration coefficient
Hi
this seems more of an issue of how people reacted to the attribute, rather than a modelling issue per se. Did you run a focus group or pilot at all?
Stephane
this seems more of an issue of how people reacted to the attribute, rather than a modelling issue per se. Did you run a focus group or pilot at all?
Stephane
- 04 Feb 2026, 11:37
- Forum: Model specification
- Topic: Combining experiments and feasibility of using nested logit structure
- Replies: 3
- Views: 41738
Re: Combining experiments and feasibility of using nested logit structure
Hi
not sure what your aim is re the alpha parameter, but otherwise, combining the models would be fine, of course with a scale parameter. There's an example on the Apollo website
Regarding NL, this won't really work. As you'll only ever have two alternatives available at a time, the probs would be ...
not sure what your aim is re the alpha parameter, but otherwise, combining the models would be fine, of course with a scale parameter. There's an example on the Apollo website
Regarding NL, this won't really work. As you'll only ever have two alternatives available at a time, the probs would be ...