polity_us_2025.R

library(tidyverse)
library(readxl)
library(tinytable)

# Load data downloaded from https://www.systemicpeace.org/inscrdata.html
polity <- read_excel("~/Downloads/p5v2018.xls") |> 
  mutate(polity_change = polity2 - lag(polity2), .by = scode) |> 
  filter(year > 1800)

# Find the biggest drops in polity scores since 1985
biggest_drops <- polity |> 
  filter(year > 1985) |> 
  filter(polity_change < -7)

polity_to_table <- biggest_drops |> 
  add_row(country = "United States", year = 2025, polity_change = -8) |> 
  arrange(polity_change) |> 
  mutate(year_range = glue::glue("{year - 1} → {year}")) |> 
  select(country, year_range, polity_change)

cbind(
  as.data.frame(slice(polity_to_table, 1:11)),
  as.data.frame(polity_to_table |> slice(12:21) |> add_row(country = ""))
) |>
  setNames(c("Country", "Year", "Polity change", "Country", "Year", "Polity change")) |>
  tt(caption = "Largest drops in Polity scores since 1985") |>
  format_tt(replace = "") |>
  style_tt(align = "llcllc") |>
  style_tt(i = 10, j = 4:6, background = "yellow") |>
  style_tt(j = 4, line = "l", line_width = 0.1, line_color = "#eeeeee")

# Plot the US over time
polity_breaks <- tribble(
  ~start, ~end, ~democracy,
  10, 5.5, "Democracy",
  5.5, -5.5, "Anocracy",
  -5.5, -10, "Autocracy"
) %>%
  mutate(democracy = fct_inorder(democracy))

polity_to_plot <- polity |> 
  add_row(country = "United States", year = c(2021, 2024, 2025), polity2 = c(8, 8, 0))

polity_to_plot |> 
  filter(country == "United States") |> 
  ggplot(aes(x = year, y = polity2, color = country)) +
  geom_rect(
    data = polity_breaks, 
    aes(xmin = -Inf, xmax = +Inf, ymin = end, ymax = start, fill = democracy),
    alpha = 0.2, inherit.aes = FALSE
  ) +
  geom_line(linewidth = 2) +
  scale_color_manual(values = "#CC503E") +
  scale_fill_manual(values = c("#009392", "#e9e29c", "#cf597e")) +
  labs(
    x = NULL,
    y = "Polity score",
    title = "Democracy in the USA (1800–2025)", 
    caption = "Source: Systemic Peace Polity Project",
    color = NULL, fill = NULL
  ) +
  theme_light(base_family = "Open Sans Light") +
  theme(
    legend.position = "bottom",
    plot.title = element_text(family = "Open Sans Condensed Bold", size = rel(1.6))
  )