geom_stream vs. geom_line

gistfile1.txt

library(tidyverse)
library(ggstream)

papers <- readr::read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/master/data/2021/2021-09-28/papers.csv')
programs <- readr::read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/master/data/2021/2021-09-28/programs.csv')
paper_programs <- readr::read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/master/data/2021/2021-09-28/paper_programs.csv')

pp <- programs %>%
  mutate(program_category = replace_na(program_category, "Technical")) %>% 
  left_join(paper_programs) %>% 
  left_join(papers) %>% 
  count(year, program_desc) %>% 
  filter(program_desc == "Development Economics" | program_desc == "Labor Studies")

ggplot(pp, aes(x = year, y = n, fill = program_desc, label = program_desc)) + 
  geom_stream(type = "ridge") +
  geom_stream_label(type = "ridge") 

ggplot(pp, aes(x = year, y = n, color = program_desc, group = program_desc)) + 
  geom_line()