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Joni Shaska

Publications and source records attributed to Joni Shaska.

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Causal Link Discovery with Unequal Edge Error Tolerance

This paper proposes a novel framework for causal discovery with asymmetric error control, called Neyman-Pearson causal discovery. Despite the importance of applications where different types of edge errors may have different importance, current state-of-the-art causal discovery algorithms do not differentiate between the types of edge errors, nor provide any finite-sample guarantees on the edge errors. Hence, this framework seeks to minimize one type of error while keeping the other below a user-specified tolerance level. Using techniques from information theory, fundamental performance limits are found, characterized by the R\'enyi divergence, for Neyman-Pearson causal discovery. Furthermore, a causal discovery algorithm is introduced for the case of linear additive Gaussian noise models, called epsilon-CUT, that provides finite-sample guarantees on the false positive rate, while staying competitive with state-of-the-art methods.

eess.SP

Bayesian causal discovery: Posterior concentration and optimal detection

We consider the problem of Bayesian causal discovery for the standard model of linear structural equations with equivariant Gaussian noise. A uniform prior is placed on the space of directed acyclic graphs (DAGs) over a fixed set of variables and, given the graph, independent Gaussian priors are placed on the associated linear coefficients of pairwise interactions. We show that the rate at which the posterior on model space concentrates on the true underlying DAG depends critically on its nature: If it is maximal, in the sense that adding any one new edge would violate acyclicity, then its posterior probability converges to 1 exponentially fast (almost surely) in the sample size $n$. Otherwise, it converges at a rate no faster than $1/\sqrt{n}$. This sharp dichotomy is an instance of the important general phenomenon that avoiding overfitting is significantly harder than identifying all of the structure that is present in the model. We also draw a new connection between the posterior distribution on model space and recent results on optimal hypothesis testing in the related problem of edge detection. Our theoretical findings are illustrated empirically through simulation experiments.

math.ST