Location: Watershed Management ResearchTitle: Learning large-scale dynamic discrete choice models of spatio-temporal preferences with application to migratory pastoralism in East Africa Author
|Ermon, Stefano - Stanford University|
|Xue, Yexiang - Cornell University - New York|
|Toth, Russell - University Of Sydney|
|Dilkina, Bistra - Georgia Tech|
|Bernstein, Richard - Cornell University - New York|
|Damoulas, Theodoros - New York City University|
|Degloria, Steve - Cornell University - New York|
|Mude, Andrew - International Livestock Research Institute (ILRI) - Kenya|
|Barrett, Christopher - Cornell University - New York|
|Gomes, Carla - Cornell University - New York|
Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 11/9/2014
Publication Date: 1/25/2015
Citation: Ermon, S., Xue, Y., Toth, R., Dilkina, B., Bernstein, R., Damoulas, T., Clark, P., Degloria, S., Mude, A., Barrett, C., Gomes, C.P. 2015. Learning large-scale dynamic discrete choice models of spatio-temporal preferences with application to migratory pastoralism in East Africa. Association for the Advancement of Artificial Intelligence.
Interpretive Summary: Resource preferences of pastoralists are often unknown to policy-makers and state-of-the-art models for inferring these preferences from data are inadequate. We studied Dynamic Discrete Choice (DDC) models from econometrics and prove that they generalize to the Max-Entropy (Inverse Reinforcement Learning) IRL model, a widely-used probabilistic approach from the machine learning literature. We developed SPL-GD, a new learning algorithm for DDC models that is considerably faster than the state of the art and scales to very large datasets. Our approach accurately modeled migratory pastoralism in East Africa, considerably outperforming other approaches, thus providing a greatly-improved opportunity to inform policy-makers of the resource preferences of pastoralists under situations of drought, resource degradation, and climate change.
Technical Abstract: Understanding spatio-temporal resource preferences is paramount in the design of policies for sustainable development. Unfortunately, resource preferences are often unknown to policy-makers and have to be inferred from data. In this paper we consider the problem of inferring agents’ preferences from observed movement trajectories, and formulate it as an Inverse Reinforcement Learning (IRL) problem. With the goal of informing policy-making, we take a probabilistic approach and consider generative models that can be used to simulate behavior under new circumstances such as changes in resource availability, access policies, or climate. We study the Dynamic Discrete Choice (DDC) models from econometrics and prove that they generalize the Max-Entropy IRL model, a widely used probabilistic approach from the machine learning literature. Furthermore, we develop SPL-GD, a new learning algorithm for DDC models that is considerably faster than the state of the art and scales to very large datasets. We consider an application in the context of pastoralism in the arid and semi-arid regions of Africa, where migratory pastoralists face regular risks due to resource availability, droughts, and resource degradation from climate change and development. We show how our approach based on satellite and survey data can accurately model migratory pastoralism in East Africa and that it considerably outperforms other approaches on a large-scale, real-world dataset of pastoralists’ movements in Ethiopia collected over 3 years.