Quantum latents: distinguishing causal scenarios with indistinguishable classical analogs

Since causal inference techniques were initially developed for causal structures with only classical latent nodes, causal scenarios where some latent nodes have other latent nodes as parents are overlooked. This omission is due to the existence of an exogenization procedure that relies on the ability to clone classical information, enabling the construction of a DAG that is observationally equivalent but includes only exogenous latent nodes. However, this procedure fails when non-classical resources are introduced, as non-classical information cannot be cloned. Consequently, a large family of causal structures involving non-classical latent nodes remains unexplored. I will present the study of the observational differences that arise when considering multilayer versions of causal scenarios.