Counterfactual Generation Under ConfoundingDownload PDF

03 Oct 2022 (modified: 05 May 2023)CML4ImpactReaders: Everyone
Keywords: Counterfactual, CycleGAN, Confounding, Correlation, Classification
TL;DR: We propose a counterfactual generation algorithm that removes the effect of confounding when augmented with observational which is usually confounded.
Abstract: A machine learning model, under the influence of observed or unobserved confounders in the training data, can learn spurious correlations and fail to generalize when deployed. For image classifiers, augmenting a training dataset using counterfactual examples has been empirically shown to break spurious correlations. However, the counterfactual generation task itself becomes more difficult as the level of confounding increases. Existing methods for counterfactual generation under confounding consider a fixed set of interventions (e.g., texture, rotation) and are not flexible enough to capture diverse data-generating processes. We formally characterize the adverse effects of confounding on any downstream tasks and show that the correlation between generative factors can be used to quantitatively measure confounding. To minimize such correlation, we propose a counterfactual generation method that learns to modify the value of any attribute in an image and generate new images. Our method is computationally efficient, simple to implement, and works well for any number of generative factors and confounding variables. Our experimental results on both synthetic (MNIST variants) and real-world (CelebA) datasets show the usefulness of our approach.
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