causal-falsify

causal-falsify: A Python library with algorithms for falsifying unconfoundedness assumption in a composite dataset from multiple sources.

This library implements algorithms proposed in our two papers based on testing independence of causal mechanisms:

• Detecting Hidden Confounding in Observational Data Using Multiple Environments – NeurIPS 2023 (pdf)
• Falsification of Unconfoundedness by Testing Independence of Causal Mechanisms – ICML 2025 (pdf)

📦 Installation & Documentation

Install from PyPI:

pip install causal-falsify

Documentation can be found at causal-falsify.readthedocs.io

Algorithms

We have implemented three falsification algorithms, which can be used complementarily:

• Hierarchical Graphical Independence Constraint (HGIC) Test:
  This test jointly assesses whether unconfoundedness and independence of causal mechanisms hold across sources. A rejection indicates that at least one of these conditions fails. The HGIC test is derived from specific d-separation using constraint-based causal discovery in a hierarchical causal graphical model.

• Mechanism Independence Test (MINT):
  Similar to the HGIC test, MINT jointly tests for unconfoundedness and independence of causal mechanisms across sources. However, it makes a parametric linearity assumption, which greatly improves sample efficiency but may lead to false positives if the linear model is severely misspecified.

• Transportability-Based Test:
  This alternative approach jointly tests for transportability and unconfoundedness across sources. A rejection here likewise indicates that at least one of these conditions does not hold.

Example usage

An example with the MINT algorithm.

from causal_falsify.algorithms.mint import MINT
from causal_falsify.utils.simulate_data import simulate_data

# Create a simulated pandas DataFrame containing where unmeasured confounding is present:
# - Observed pre-treatment covariates: ["X_0", "X_1"]
# - Source label: "S"
# - Treatment: "A"
# - Outcome: "Y"
confounded_data = simulate_data(
    n_samples=250, conf_strength=1.0, n_envs=10, n_observed_confounders=2
)

# Run the MINT algorithm
mint_algorithm = MINT(binary_treatment=False, binary_outcome=False)
p_value = mint_algorithm.test(
    confounded_data,
    covariate_vars=["X_0", "X_1"],
    treatment_var="A",
    outcome_var="Y",
    source_var="S",
)

# We are evaluating the joint null hypothesis of no unmeasured confounding 
# and independent causal mechanisms across sources.
# Reject the null if p-value < significance level (e.g., 0.05).
print("p-value:", p_value)
print("reject null:",  p_value < 0.05)

📄 Please cite our work if you use our package

The HGIC and MINT algorithms are based on two of our papers which you can cite as follows:

@article{karlsson2023detecting,
  title={Detecting hidden confounding in observational data using multiple environments},
  author={Karlsson, Rickard and Krijthe, Jesse H},
  journal={Advances in Neural Information Processing Systems},
  volume={36},
  pages={44280--44309},
  year={2023}
}

@inproceedings{karlsson2025falsification,
  title={Falsification of Unconfoundedness by Testing Independence of Causal Mechanisms},
  author={Karlsson, Rickard and Krijthe, Jesse H},
  booktitle={International Conference on Machine Learning},
  organization={PMLR}
  year={2025},
}

🐛 Issues

If you encounter any bugs, unexpected behavior, or have questions about using the package, please don’t hesitate to open an issue.

📬 Contact

Created by Rickard Karlsson – feel free to reach out!