---
title: "Session 6 — Democracy predictor"
author: "Prof. Dae-Jin Lee (daelee@faculty.ie.edu)"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE, message = FALSE, warning = FALSE)
library(tidyverse)
ci <- read_csv("data/country_indicators.csv")
```

```{r}
fit_d <- lm(life_expectancy ~ democracy_score, data = ci)
coef(fit_d)
summary(fit_d)$r.squared

# Binary X link
fit_c <- lm(life_expectancy ~ recent_internal_conflict, data = ci)
coef(fit_c)
ci |>
  group_by(recent_internal_conflict) |>
  summarise(mean_le = mean(life_expectancy), .groups = "drop")
```