Add Average potential outcome model

[SvenKlaassen]

Average Potential Outcomes

Adding DoubleMLAPO to estimate (weighted) average potential outcomes

$$\theta_0 = \mathbb{E}[\omega(Y,D,X) \cdot Y(a)]$$

for some treatment value $D=a$.

Further adding DoubleMLAPOS to simultaneously compute multiple discrete average potential outcomes and effects.

New DGP

New dgp make_irm_data_discrete_treatements.

Additional updates

Add optional treatment_names and summary to DoubleMLFramework.

Reference to Issues or PRs

First step to implement #245

Comments

DoubleMLAPO supports:

• Sensitivity analysis
• weights
• External predictions
• Tuning
• Conditional and group estimates

DoubleMLAPOS supports:

• Sensitivity analysis
• Benchmarking
• weights
• External predictions

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