Causal Inference on Discrete Data via Estimating Distance Correlations

In this article, we deal with the problem of inferring causal directions when the data are on discrete domain. By considering the distribution of the cause [Formula: see text] and the conditional distribution mapping cause to effect [Formula: see text] as independent random variables, we propose to infer the causal direction by comparing the distance correlation between [Formula: see text] and [Formula: see text] with the distance correlation between [Formula: see text] and [Formula: see text]. We infer that X causes Y if the dependence coefficient between [Formula: see text] and [Formula: see text] is smaller. Experiments are performed to show the performance of the proposed method.