THE ACCURACY OF THE MULTINOMIAL LOGIT MODEL AS AN APPROXIMATION TO THE MULTINOMIAL PROBIT MODEL OF TRAVEL DEMAND

The multinomial probit model of travel demand is considerably more general but much less tractable than the better-known multinomial logit model. In an effort to determine the effects of using the relatively simple logit model in situations where the assumptions of probit modeling are satisfied but those of logit modeling are not, the accuracy of the multinomial logit model as an approximation to a variety of three-alternative probit models has been evaluated. Multinomial logit can give highly erroneous estimates of the choice probabilities of multinomial probit models. However, logit models appear to give asymptotically accurate estimates of the ratios of the coefficients of the systematic components of probit utility functions, even when the logit choice probabilities differ greatly from the probit ones. Large estimation data sets are not necessarily needed to enable likelihood ratio tests to distinguish three-alternative probit models from logit models that give seriously erroneous estimates of the probit choice probabilities. Inclusion of alternative-specific dummy variables in logit utility functions cannot be relied upon to reduce significantly the errors of logit approximations to the choice probabilities of probit models whose utility functions do not contain the dummies. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01912615
• Corporate Authors:

  Pergamon Press, Incorporated

  Headington Hill Hall
  Oxford OX30BW,    
• Authors:
  • Horowitz, J
• Publication Date: 1980-12

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 331-341
• Serial:
  • Transportation Research Part B: Methodological
  • Volume: 14B
  • Issue Number: 4
  • Publisher: Elsevier
  • ISSN: 0191-2615
  • Serial URL: http://www.sciencedirect.com/science/journal/01912615

Subject/Index Terms

• TRT Terms: Accuracy; Alternatives analysis; Choice models; Demand; Discrete systems; Logits; Mathematical models; Probability theory; Probits; Transportation; Travel demand
• Uncontrolled Terms: Discontinuous
• ITRD Terms: 285: Demand (econ); 9015: Discontinuous; 6440: Error; 6473: Mathematical model; 1155: Transport
• Subject Areas: Operations and Traffic Management; Planning and Forecasting; Transportation (General); I71: Traffic Theory;

Filing Info

• Accession Number: 00334076
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Sep 16 1981 12:00AM