PA.NUS.PPPC.RF %>%
filter(iso2c %in% c("JP", "DE", "CH", "KR")) %>%
left_join(iso2c, by = "iso2c") %>%
mutate(Iso2c = ifelse(iso2c == "KR", "Korea", Iso2c)) %>%
year_to_date %>%
left_join(colors, by = c("Iso2c" = "country")) %>%
ggplot(.) + xlab("") + ylab("Price level ratio of PPP conversion factor (GDP)\nto market exchange rate") +
geom_line(aes(x = date, y = value, color = color)) +
theme_minimal() + scale_color_identity() + add_4flags +
scale_x_date(breaks = seq(1950, 2100, 5) %>% paste0("-01-01") %>% as.Date,
labels = date_format("%Y")) +
scale_y_log10(breaks = seq(0.1, 2, 0.1))