From iris.vanermen at kuleuven.be Wed Jul 28 08:18:02 2021 From: iris.vanermen at kuleuven.be (Iris Vanermen) Date: Tue, 27 Jul 2021 22:18:02 +0000 Subject: [Limdep Nlogit List] Pds specification for choice modeling with unbalanced datasets Message-ID: <0b35a8c3d86e4f5f944d9523e6d77d04@ICTS-S-EXMBX17.luna.kuleuven.be> Dear Mr., Ms., I am trying to estimate a random parameters logit model in which the number of choice tasks differs between individuals. For this, I am trying to adjust the Pds specification with a variable indicating the number of choice cards per individual but I get following error: "Error 1081: Mismatch of # indivs. and number implied by groups" that I do not seem to be able to resolve. How should I specify Pds in case of different number of choice cards per individual? Many thanks! Best regards, Iris Vanermen From wgreene at stern.nyu.edu Wed Jul 28 09:10:18 2021 From: wgreene at stern.nyu.edu (William Greene) Date: Tue, 27 Jul 2021 19:10:18 -0400 Subject: [Limdep Nlogit List] Pds specification for choice modeling with unbalanced datasets In-Reply-To: <0b35a8c3d86e4f5f944d9523e6d77d04@ICTS-S-EXMBX17.luna.kuleuven.be> References: <0b35a8c3d86e4f5f944d9523e6d77d04@ICTS-S-EXMBX17.luna.kuleuven.be> Message-ID: Iris. The unbalanced choice model has a complicated data set. Observations (rows of data) are grouped within a choice task, and there is a panel of choice tasks. NLOGIT handles this case by borrowing part of the process from the ordinary panel data routine. The match of the data to the specification ends up being checked twice, once as if it were an ordinary panel and a second time by the RPLogit routine. (There is a description in Section N29.10 in the manual how this is set up - you would have used the guide there to set up the data.) The diagnostic you received is generated by the first pass through the data. But, this can be ignored. It is the second pass that actually tallies the panel setup for RPLogit. So, if your data are arranged as the estimator expects, you can ignore that diagnostic. (It should be a warning, not an error.) Regards, Bill Greene On Tue, Jul 27, 2021 at 6:25 PM Iris Vanermen wrote: > Dear Mr., Ms., > > I am trying to estimate a random parameters logit model in which the > number of choice tasks differs between individuals. For this, I am trying > to adjust the Pds specification with a variable indicating the number of > choice cards per individual but I get following error: "Error 1081: > Mismatch of # indivs. and number implied by groups" that I do not seem to > be able to resolve. How should I specify Pds in case of different number of > choice cards per individual? > > Many thanks! > Best regards, > Iris Vanermen > _______________________________________________ > Limdep site list > Limdep at mailman.sydney.edu.au > https://protect-au.mimecast.com/s/Z5V9CK1DvKT2mDwRgIMRrZF?domain=limdep.itls.usyd.edu.au > > -- William Greene Department of Economics, emeritus Stern School of Business, New York University 44 West 4 St. New York, NY, 10012 URL: https://protect-au.mimecast.com/s/DLgGCL7EwMfR4kOzxsq9G0r?domain=people.stern.nyu.edu Email: wgreene at stern.nyu.edu Editor in Chief: Journal of Productivity Analysis Editor in Chief: Foundations and Trends in Econometrics Associate Editor: Economics Letters Associate Editor: Journal of Business and Economic Statistics