This function takes fully prepared data (with all auxilliary columns from the necessary models) and estimates average treatment effects using AIPW.

`calculate_ate(data)`

- data
The dataset of interest after it has been prepared fully.

Kennedy, E. H. (2020). Towards optimal doubly robust estimation of heterogeneous causal effects.

*arXiv preprint arXiv:2004.14497*.Tsiatis, A. A., Davidian, M., Zhang, M., & Lu, X. (2008). Covariate adjustment for two‐sample treatment comparisons in randomized clinical trials: a principled yet flexible approach.

*Statistics in medicine*, 27(23), 4658-4677.