Deep Multi-Modal Structural Equations For Causal Effect Estimation With Unstructured Proxies

Estimating the effect of an intervention while accounting for confounding variables is a key task in causal inference. Oftentimes, the confounders are unobserved, but we have access to large amounts of unstructured data (images, text) that contain valuable proxy signal about the missing confounders. This paper demonstrates that leveraging unstructured data that is often left unused by existing algorithms improves the accuracy of causal effect estimation. Specifically, we introduce deep multi-modal structural equations, a generative model in which confounders are latent variables and unstructured data are proxy variables. This model supports multiple multi-modal proxies (images, text) as well as missing data. We empirically demonstrate on tasks in genomics and healthcare that our approach corrects for confounding using unstructured inputs, potentially enabling the use of large amounts of data that were previously not used in causal inference.