Causal Discovery on Discrete Data with Extensions to Mixture Model

In this article, we deal with the causal discovery problem on discrete data. First, we present a causal discovery method for traditional additive noise models that identifies the causal direction by analyzing the supports of the conditional distributions. Then, we present a causal mixture model to address the problem that the function transforming cause to effect varies across the observations. We propose a novel method called Support Analysis (SA) for causal discovery with the mixture model. Experiments using synthetic and real data are presented to demonstrate the performance of our proposed algorithm.