L4-10 · Causal machine learning, transport, and fairness
Define a causal learning target and explain the additional assumptions needed for transport and fairness claims.
Learn¶
Causal machine learning can estimate outcome regressions, treatment probabilities, or treatment effect variation. Flexible prediction methods do not create identification. Start with a defined population, intervention, outcome, and time horizon. Then state exchangeability, consistency, positivity, and any other assumptions required for the chosen target.
Transport asks whether results from one population or environment apply to another. If only the distribution of measured effect modifiers changes, valid stratum effects can sometimes be reweighted to the target distribution. This requires stable relevant mechanisms and enough source data in target strata. Unmeasured mechanism changes can defeat this strategy.
Fairness is partly a choice of social objective. Equal predictive error rates and counterfactual fairness are different criteria and can conflict. A causal fairness claim needs a justified graph and normative decisions about acceptable paths. Removing a protected attribute from inputs does not remove its information from correlated variables.
Practice¶
Solution
The weighted effect is 0.25(2)+0.75(-1)=-0.25. This is a target-population causal average under the assumptions. It does not establish fairness, which needs a stated criterion and further justification.
Check your understanding¶
What must come before fitting a causal effect learner?
A. A guarantee that all populations share one effect
B. A choice to remove every demographic variable
C. A defined causal target and justified identification assumptions
Show the answer
C. A defined causal target and justified identification assumptions
A learner estimates quantities within a causal analysis. The intervention target and identification assumptions determine whether its estimates answer the intended causal question.
Sources¶
This lesson draws on Hernan & Robins, 2020Schölkopf et al., 2021Peters et al., 2015.
Next: L5-01 · States and the Born rule
- Hernan, M., & Robins, J. (2020). Causal Inference: What If. https://miguelhernan.org/whatifbook
- Schölkopf, B., Locatello, F., Bauer, S., Ke, N. R., Kalchbrenner, N., Goyal, A., & Bengio, Y. (2021). Towards Causal Representation Learning. https://arxiv.org/abs/2102.11107
- Peters, J., Bühlmann, P., & Meinshausen, N. (2015). Causal inference using invariant prediction: identification and confidence intervals. https://arxiv.org/abs/1501.01332
- Bareinboim, E. (2025). Causal Artificial Intelligence: A Roadmap for Building Causally Intelligent Systems. https://causalai-book.net/