# OutcomeWeights - Extending Treatment Effect Estimation

## Overview

This repository contains the implementation of **Task 2** for the Causal Machine Learning group assignment. The focus is on extending the functionality of the `OutcomeWeights` package to support additional treatment effect estimators, including ATT, ATU, Overlap, and LATE. The project also includes replication of balancing checks and numerical equivalence tests for the new estimators.

## Repository Structure

```

OutcomeWeights-Extensions/

│

├── README.md                # Overview of the project (this file)

├── LICENSE                  # License for the project

├── .gitignore               # Files and folders to exclude from version control

├── data/                    # Placeholder for datasets or details on accessing them

│   └── README.md            # Instructions for dataset usage

├── notebooks/               # R notebooks for replication and analysis

│   ├── Notebook_Average.Rmd

│   ├── Notebook_Heterogeneous.Rmd

│   └── README.md            # Descriptions of the notebooks

├── scripts/                 # R scripts for estimator implementation

│   ├── Task2_StartingPoint.R

│   └── OutcomeWeights_Extensions.R

├── slides/                  # Presentation slides summarizing findings

│   └── Task2_Pitch.pdf

├── docs/                    # Additional documentation and references

│   └── references.md        # Links to related research and materials

```

## Installation

1. Clone this repository using HTTPS:

   ```bash

   git clone https://github.com/PulkitT01/CausalML-OutcomeWeights-Extensions.git

   ```

2. Install required R packages:

   ```R

   install.packages(c("grf", "hdm", "OutcomeWeights"))

   ```

3. Open the R notebooks or scripts to explore and run the analysis.

## Objectives

1. Extend the `OutcomeWeights` package to implement the following treatment effect estimators:

   - **ATT** (Average Treatment Effect on the Treated)

   - **ATU** (Average Treatment Effect on the Untreated)

   - **Overlap** (Average Treatment Effect in the Overlap Region)

   - **LATE** (Local Average Treatment Effect)

2. Replicate balancing checks for the new estimators to validate numerical equivalence.

3. Document challenges faced and solutions implemented.

## Usage

- **Scripts**:

  - `Task2_StartingPoint.R`: Provides the initial script for implementing additional estimators.

  - `OutcomeWeights_Extensions.R`: Contains the completed implementation for ATT, ATU, Overlap, and LATE estimators.

- **Notebooks**:

  - `Notebook_Average.Rmd` and `Notebook_Heterogeneous.Rmd`: Contain replication of treatment effect estimations for numerical validation.

## Results

The results demonstrate the successful implementation and replication of:

1. **ATT (Average Treatment Effect on the Treated):**

   - Numerical equivalence validated.

2. **ATU (Average Treatment Effect on the Untreated):**

   - Numerical equivalence validated.

3. **Overlap (Average Treatment Effect in the Overlap Region):**

   - Numerical equivalence validated.

4. **LATE (Local Average Treatment Effect):**

   - Numerical equivalence validated.

## Challenges and Solutions

- **Reverse-engineering package functionalities:** Required detailed exploration of the `grf` and `OutcomeWeights` implementations to extend compatibility.

- **Adapting balancing checks:** Implemented custom residual-on-residual regression for the Overlap estimator.

- **Numerical equivalence:** Validated results through comparisons with package outputs and manual calculations.

## References

- [OutcomeWeights GitHub Repository](https://github.com/MCKnaus/OutcomeWeights)

- [Generalized Random Forests (grf)](https://github.com/grf-labs/grf)

- [Research Paper: "Treatment Effects as Weighted Outcomes"](https://doi.org/10.48550/arXiv.2411.11559)

## License

This project is licensed under the MIT License - see the `LICENSE` file for details.

## Contact

For questions or feedback, please contact:

- **Pulkit Thukral** (*[pulkit.thukral@student.uni-tuebingen.de](mailto:pulkit.thukral@student.uni-tuebingen.de)*)

- **Jiha Kim** (*[jiha.kim@student.uni-tuebingen.de](mailto:jiha.kim@student.uni-tuebingen.de)*)

- **Sumitrra Bala Subramaniam** (*[sumitrra.bala-subramaniam@student.uni-tuebingen.de](mailto:sumitrra.bala-subramaniam@student.uni-tuebingen.de)*)

- **Timothy Leske** (*[timothy.leske@student.uni-tuebingen.de](mailto:timothy.leske@student.uni-tuebingen.de)*)