HUMAN CAPITAL INDEX MAPS

MAPPING THE HUMAN CAPITAL INDEX VARIOUS WAYS IN R

Robert Myles McDonnell

3 minute read

This post got lost mysteriously when I transitioned to Netlify – just reposting. It was originally from June 2017.

I’m not too sure that the Human Capital Index is a reliable measure of what it’s supposed to measure, but I’m convinced by Deirdre McCloskey’s eloquent arguments that it is Human Capital, or ingenuity, in less dry terms, that has made the modern world (in conjunction with freedom and some basic legal structures). However, all that interesting talk aside, there are now quite a few new ways to make maps in R. The sf package has synced up with the dev version of ggplot2 to produce geom_sf(), tmaps brings some cool themes to ggplot maps and mapmate has been used to produce some stunning visualizations. Hence, I thought I’d use the HCI to check these out.

library(rvest)
library(ggplot2)
library(dplyr)
## Warning: package 'dplyr' was built under R version 3.4.2
hci <- read_html("http://reports.weforum.org/human-capital-report-2016/rankings/") %>%
  html_node("table") %>% html_table() %>% 
  rename(country = Economy, rank = `Overall Rank`, human_capital = `Overall Score`) %>% 
  mutate(country = recode(country, 
                          'Russian Federation' = 'Russia',
                          'United Kingdom' = 'UK',
                          'United States' = 'USA',
                          'Korea, Rep.' = 'South Korea',
                          'Kyrgyz Republic' = 'Kyrgyzstan',
                          'Slovak Republic' = 'Slovakia',
                          'Macedonia, FYR' = 'Macedonia',
                          'Iran, Islamic Rep.' = 'Iran',
                          'Trinidad and Tobago' = 'Trinidad',
                          'Lao PDR' = 'Laos',
                          'CÙte d’Ivoire' = 'Ivory Coast'))

I used to make maps in ggplot style with shapefiles, fortify and so on. The upside is that there are lots of shapefiles available, but the downsides are that the dataframes you end up with are usually pretty big. There’s a map_data() function in the ggplot2 package that grabs some polygon data. The vanilla map we can make with these functions looks like this (with theme_minimal() to prettify things):

globe <- map_data("world") %>% rename(country = region)


world <- left_join(globe, hci)


ggplot(data = world, aes(x = long, y = lat, group = group)) +
  geom_polygon(aes(fill = human_capital)) + 
  theme_minimal()

Not bad. You can mess around with the projections using coord_map(), but it still feels a long way from Mike Bostock’s amazing d3 maps (I know, d3 is more geared towards presentation. Still…). Let’s use coord_map():

ggplot(data = world, aes(x = long, y = lat, group = group)) +
  geom_polygon(aes(fill = human_capital)) +
  coord_map(projection = "gilbert") + 
  theme_minimal()

ggplot(data = world, aes(x = long, y = lat, group = group)) +
  geom_polygon(aes(fill = human_capital)) +
  coord_map(projection = "azequidistant") + 
  theme_minimal()

So let’s try the sf method. I’m getting a dataset of world ‘geometry’ coordinates (a list-column in the sf dataframe) from the rnaturalearth package.

library(rnaturalearth)
library(sf)

countries <- ne_countries(returnclass = "sf") %>% 
  rename(country = sovereignt) %>% 
  select(country, geometry) %>% 
  mutate(country = recode(country, 
                          "United States of America" = "USA",
                          "United Kingdom" = "UK")) %>% 
  left_join(hci)

ggplot(countries) + 
  geom_sf(aes(fill = human_capital), size = 0.2) +
  theme_minimal()

The sf map doesn’t look massively better than that created with geom_polygon() (it’s much more in proportion, as I haven’t changed figure sizes in this RMarkdown document), although the process feels more intuitive to me. The dataframe feels ‘tidier’, as it still has the country as the unit of analysis – in other words, the dataframe we’re using has 177 rows, as opposed to tens of thousands. Let’s try some themes with tmap.

library(tmap)

tm_shape(countries) +
    tm_polygons("human_capital", title="Human Capital Index") +
tm_format_World() +
tm_style_grey()

Ooh, that’s nice. The theme actually makes it easier to see what’s going on: the difference between Canada & the US was not so apparent before. (Canada’s score is 81.95 as opposed to 78.86 for the US…so precise, these numbers.)

So in terms of how things look, using this basic code, tmap comes out well. I don’t really like its syntax though, it reminds me of qplot(). I prefer the full ggplot() approach myself.

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