An economically-consistent discrete choice model with flexible utility specification based on artificial neural networks
This work addresses the problem of deriving interpretable economic outcomes in discrete choice modeling for researchers and practitioners, representing an incremental improvement by integrating neural networks with established economic assumptions.
The paper tackles the challenge of specifying utility functions in random utility maximization models by proposing a neural network-based discrete choice model (ASS-NN) that balances flexibility with economic consistency, showing it outperforms conventional multinomial logit models in goodness of fit on synthetic and real datasets.
Random utility maximisation (RUM) models are one of the cornerstones of discrete choice modelling. However, specifying the utility function of RUM models is not straightforward and has a considerable impact on the resulting interpretable outcomes and welfare measures. In this paper, we propose a new discrete choice model based on artificial neural networks (ANNs) named "Alternative-Specific and Shared weights Neural Network (ASS-NN)", which provides a further balance between flexible utility approximation from the data and consistency with two assumptions: RUM theory and fungibility of money (i.e., "one euro is one euro"). Therefore, the ASS-NN can derive economically-consistent outcomes, such as marginal utilities or willingness to pay, without explicitly specifying the utility functional form. Using a Monte Carlo experiment and empirical data from the Swissmetro dataset, we show that ASS-NN outperforms (in terms of goodness of fit) conventional multinomial logit (MNL) models under different utility specifications. Furthermore, we show how the ASS-NN is used to derive marginal utilities and willingness to pay measures.