---
title: "PP5001 — Problem Set 1"
subtitle: "Matching and Propensity-Score Weighting"
author: "Student ID: ..."
format:
  pdf:
    papersize: a4
    fontsize: 11pt
    geometry: margin=25mm
    toc: false
execute:
  echo: true
  warning: true
  error: false
jupyter: python3
---

**Due: Friday 2 October 2026, 12 noon (UK time).**

Follow the [problem-set instructions](https://www.djaeger.org/teaching/mpp/pp5001/exercises/02-matching.html). Submit this completed `.qmd` and its rendered PDF through Moodle. Download the original Stata files as directed and keep them in a `data` folder beside this file.

## Setup and data import

```{python}
from pathlib import Path
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import statsmodels.formula.api as smf

# Import the downloaded Stata files and prepare your samples here.
# Keep re74 in each sample from the start. It enters the score model in Question 5.
# Fit propensity scores using both treated and comparison observations.
```

**Chosen comparison samples:** ...

## 1. The experimental benchmark

```{python}
# Your code here
```

**Interpretation:** ...

## 2. Replace the experimental controls

```{python}
# Your code here
```

**Interpretation:** ...

## 3. Estimate propensity scores and examine common support

```{python}
# Your code here
```

**Interpretation:** ...

## 4. Weighting to estimate the effect on the treated

```{python}
# Your code here
```

**Interpretation:** ...

## 5. What does pre-treatment earnings history add?

```{python}
# Your code here
```

**Interpretation:** ...

## 6. What have we learned?

```{python}
# Your code here
```

**Interpretation:** ...

## AI-use declaration

Complete this declaration before submitting. If you did not use AI, write “I did not use AI tools for this assignment.”

**AI tools used (including model or version, if known):** [Enter the tools used.]

**How I used them:** [Identify the questions or parts of the assignment where you used AI, and describe its contribution to your code, analysis, explanations, or presentation.]

**How I checked the work:** [Explain how you verified the code, results, and claims, and describe any corrections or revisions you made.]

I take responsibility for the accuracy of the submitted work and can explain the code and analysis it contains.