  Imitation learning methods are used to infer a policy in a Markov decision
process from a dataset of expert demonstrations by minimizing a divergence
measure between the empirical state occupancy measures of the expert and the
policy. The guiding signal to the policy is provided by the discriminator used
as part of an versarial optimization procedure. We observe that this model is
prone to absorbing spurious correlations present in the expert data. To
alleviate this issue, we propose to use causal invariance as a regularization
principle for adversarial training of these models. The regularization
objective is applicable in a straightforward manner to existing adversarial
imitation frameworks. We demonstrate the efficacy of the regularized
formulation in an illustrative two-dimensional setting as well as a number of
high-dimensional robot locomotion benchmark tasks.
