Important: Read this before posting to this forum
- 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.
- 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
- Before asking a question on the forum, users are kindly requested to follow these steps:
- Check that the same issue has not already been addressed in the forum - there is a search tool.
- 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
- Check the frequently asked questions section on the Apollo website, which discusses some common issues/failures. Please see http://www.apollochoicemodelling.com/faq.html
- Make sure that R is using the latest official release of Apollo.
- Users can check which version they are running by entering packageVersion("apollo").
- Then check what is the latest full release (not development version) at http://www.ApolloChoiceModelling.com/code.html.
- To update to the latest official version, just enter install.packages("apollo"). To update to a development version, download the appropriate binary file from http://www.ApolloChoiceModelling.com/code.html, and install the package from file
- If the above steps do not resolve the issue, then users should follow these steps when posting a question:
- provide full details on the issue, including the entire code and output, including any error messages
- 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 6 matches
- 02 Apr 2024, 19:05
- Forum: Post-estimation analysis/use of results
- Topic: Marginal rate of substitution for different sociodemographic groups
- Replies: 3
- Views: 557
Re: Marginal rate of substitution for different sociodemographic groups
Dear Prof. Hess, Thank you for the reply. Is it must to add socio-demographic variables in randcoeff to get MRS for different SD group? Instead can't it be obtained just by splitting the data base for the SD group of interest and calculating MRS? I attempted to conduct the analysis by changing the d...
- 31 Mar 2024, 17:54
- Forum: Post-estimation analysis/use of results
- Topic: Marginal rate of substitution for different sociodemographic groups
- Replies: 3
- Views: 557
Marginal rate of substitution for different sociodemographic groups
Dear Prof. Hess. I recently estimated a mixed logit model and calculated two different Marginal Rate of Substitution (MRS) indicators for the entire sample in the following way: randcoeff[["b_tt"]] = -exp( mu_log_b_tt + sigma_log_b_tt * draws_tt ) randcoeff[["b_info"]] = exp(mu_l...
- 03 Mar 2024, 15:53
- Forum: Post-estimation analysis/use of results
- Topic: WTP distribution in preference space
- Replies: 3
- Views: 2102
Re: WTP distribution in preference space
Hi Prof. Stephane, Thank you for your insights on the matter. Following your suggestions, I made increased the number of draws to 120k (earlier it was 50k) and removing the limits for the axes. Despite these modifications, the density plots have remained largely unchanged. What else can I try here? ...
- 20 Feb 2024, 18:20
- Forum: Post-estimation analysis/use of results
- Topic: WTP distribution in preference space
- Replies: 3
- Views: 2102
WTP distribution in preference space
Dear Prof. Hess, I have developed a mixed logit model and want to calculate 'Value of Risk Reduction (VRR)' from the two random parameters used in the model. First parameter is travel time (negative log normal distribution) and second is 'Safety information' (positive log normal). I have the followi...
- 13 Feb 2024, 16:06
- Forum: Post-estimation analysis/use of results
- Topic: Difference in Marginal rate of substitution between MNL and Mixed logit models
- Replies: 1
- Views: 44
Difference in Marginal rate of substitution between MNL and Mixed logit models
Dear Prof. Stephane, I have a question concerning the difference in the marginal rate of substitution values for the Multinomial Logit (MNL) and Mixed Logit models. Specifically, I am calculating 'Value of Risk Reduction,' which is the additional travel time food delivery riders are willing to under...
- 09 Feb 2024, 13:00
- Forum: Post-estimation analysis/use of results
- Topic: Out of sample results
- Replies: 3
- Views: 1735
Re: Out of sample results
Dear Prof. Stephane, I hope this email finds you well. I have some follow-up questions regarding the same topic. How should we interpret the average difference in log-likelihood (LL) between the estimated sample and validation sample? Does a smaller value for percentage difference imply that the est...