Generative invariance: causal extrapolation without exogeneity

We present a new estimator for predicting outcomes in different distributional settings under hidden confounding without relying on instruments or exogenous variables. The population definition of our estimator identifies causal parameters, whose empirical version is plugged into a generative model capable of replicating the conditional law within a test environment. We check that the probabilistic affinity between our proposal and test distributions is invariant across interventions. This work enhances the current statistical comprehension of causality by demonstrating that predictions in a test environment can be made without the need for exogenous variables and without specific assumptions regarding the strength of perturbations or the overlap of distributions.