The main intent of the tidycensus package is to return population characteristics of the United States in tidy format allowing for integration with simple feature geometries. Its intent is not, and has never been, to wrap the universe of APIs and datasets available from the US Census Bureau. For datasets not included in tidycensus, I recommend Hannah Recht’s censusapi package (https://github.com/hrecht/censusapi), which allows R users to access all Census APIs, and packages such as Jamaal Green’s lehdr package (https://github.com/jamgreen/lehdr) which grants R users access to Census Bureau LODES data.
However, tidycensus will ultimately incorporate a select number of Census Bureau datasets outside the decennial Census and ACS that are aligned with the basic goals of the package. One such dataset is the Population Estimates API, which includes information on a wide variety of population characteristics that is updated annually.
Population estimates are available in tidycensus through the get_estimates() function. Estimates are organized into products, which in tidycensus include "population", "components", "housing", and "characteristics". The population and housing products contain population/density and housing unit estimates, respectively. The components of change and characteristics products, in contrast, include a wider range of possible variables.
Components of change population estimates
By default, specifying "population", "components", or "housing" as the product in get_estimates() returns all variables associated with that component. For example, we can request all components of change variables for US states in 2017:
library(tidycensus) library(tidyverse) options(tigris_use_cache = TRUE) us_components <- get_estimates(geography = "state", product = "components") us_components
## # A tibble: 624 x 4
## NAME GEOID variable value
## <chr> <chr> <chr> <dbl>
## 1 Alabama 01 BIRTHS 59637
## 2 Alaska 02 BIRTHS 11335
## 3 Arizona 04 BIRTHS 86765
## 4 Arkansas 05 BIRTHS 38779
## 5 California 06 BIRTHS 500353
## 6 Colorado 08 BIRTHS 66345
## 7 Connecticut 09 BIRTHS 36319
## 8 Delaware 10 BIRTHS 11026
## 9 District of Columbia 11 BIRTHS 9652
## 10 Florida 12 BIRTHS 221755
## # … with 614 more rowsThe variables included in the components of change product consist of both estimates of counts and rates. Rates are preceded by an R in the variable name and are calculated per 1000 residents.
unique(us_components$variable)
## [1] "BIRTHS" "DEATHS" "DOMESTICMIG"
## [4] "INTERNATIONALMIG" "NATURALINC" "NETMIG"
## [7] "RBIRTH" "RDEATH" "RDOMESTICMIG"
## [10] "RINTERNATIONALMIG" "RNATURALINC" "RNETMIG"Available geographies include "us", "state", "county", "metropolitan statistical area/micropolitan statistical area", and "combined statistical area".
If desired, users can request a specific component or components by supplying a character vector to the variables parameter, as in other tidycensus functions. get_estimates() also supports simple feature geometry integration to facilitate mapping. In the example below, we’ll acquire data on the net migration rate between 2016 and 2017 for all counties in the United States, and request shifted and re-scaled feature geometry for Alaska and Hawaii to facilitate national mapping.
net_migration <- get_estimates(geography = "county", variables = "RNETMIG", geometry = TRUE, shift_geo = TRUE) net_migration
## Simple feature collection with 3142 features and 4 fields
## geometry type: MULTIPOLYGON
## dimension: XY
## bbox: xmin: -2100000 ymin: -2500000 xmax: 2516374 ymax: 732103.3
## CRS: +proj=laea +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +a=6370997 +b=6370997 +units=m +no_defs
## # A tibble: 3,142 x 5
## GEOID NAME variable value geometry
## <chr> <chr> <chr> <dbl> <MULTIPOLYGON [m]>
## 1 01001 Autauga Cou… RNETMIG -1.86 (((1269841 -1303980, 1248372 -1300830, 12…
## 2 01009 Blount Coun… RNETMIG -1.29 (((1240383 -1149119, 1222632 -1143475, 12…
## 3 01017 Chambers Co… RNETMIG 1.59 (((1382944 -1225846, 1390214 -1235634, 13…
## 4 01021 Chilton Cou… RNETMIG -1.78 (((1257515 -1230045, 1259055 -1240041, 12…
## 5 01033 Colbert Cou… RNETMIG 0.919 (((1085910 -1080751, 1085892 -1080071, 10…
## 6 01045 Dale County… RNETMIG -3.48 (((1382203 -1366760, 1387076 -1400145, 13…
## 7 01051 Elmore Coun… RNETMIG 2.51 (((1278144 -1255151, 1279961 -1256403, 13…
## 8 01065 Hale County… RNETMIG -4.12 (((1176099 -1258997, 1172005 -1264523, 11…
## 9 01079 Lawrence Co… RNETMIG -8.08 (((1178216 -1055420, 1179636 -1066254, 11…
## 10 01083 Limestone C… RNETMIG 7.69 (((1197770 -1018013, 1199180 -1017791, 12…
## # … with 3,132 more rowsWe’ll next use tidyverse tools to generate a groups column that bins the net migration rates into comprehensible categories, and plot the result using geom_sf() and ggplot2.
order = c("-15 and below", "-15 to -5", "-5 to +5", "+5 to +15", "+15 and up") net_migration <- net_migration %>% mutate(groups = case_when( value > 15 ~ "+15 and up", value > 5 ~ "+5 to +15", value > -5 ~ "-5 to +5", value > -15 ~ "-15 to -5", TRUE ~ "-15 and below" )) %>% mutate(groups = factor(groups, levels = order)) ggplot() + geom_sf(data = net_migration, aes(fill = groups, color = groups), lwd = 0.1) + geom_sf(data = tidycensus::state_laea, fill = NA, color = "black", lwd = 0.1) + scale_fill_brewer(palette = "PuOr", direction = -1) + scale_color_brewer(palette = "PuOr", direction = -1, guide = FALSE) + coord_sf(datum = NA) + theme_minimal(base_family = "Roboto") + labs(title = "Net migration per 1000 residents by county", subtitle = "US Census Bureau 2017 Population Estimates", fill = "Rate", caption = "Data acquired with the R tidycensus package | @kyle_e_walker")
Estimates of population characteristics
The fourth population estimates product available in get_estimates(), "characteristics", is formatted differently than the other three. It returns population estimates broken down by categories of AGEGROUP, SEX, RACE, and HISP, for Hispanic origin. Requested breakdowns should be specified as a character vector supplied to the breakdown parameter when the product is set to "characteristics".
By default, the returned categories are formatted as integers that map onto the Census Bureau definitions explained here: https://www.census.gov/data/developers/data-sets/popest-popproj/popest/popest-vars/2017.html. However, by specifying breakdown_labels = TRUE, the function will return the appropriate labels instead. For example:
la_age_hisp <- get_estimates(geography = "county", product = "characteristics", breakdown = c("SEX", "AGEGROUP", "HISP"), breakdown_labels = TRUE, state = "CA", county = "Los Angeles") la_age_hisp
## # A tibble: 210 x 6
## GEOID NAME value SEX AGEGROUP HISP
## <chr> <chr> <dbl> <chr> <fct> <chr>
## 1 06037 Los Angeles County, C… 10105518 Both sex… All ages Both Hispanic …
## 2 06037 Los Angeles County, C… 5190231 Both sex… All ages Non-Hispanic
## 3 06037 Los Angeles County, C… 4915287 Both sex… All ages Hispanic
## 4 06037 Los Angeles County, C… 2529798 Male All ages Non-Hispanic
## 5 06037 Los Angeles County, C… 4981895 Male All ages Both Hispanic …
## 6 06037 Los Angeles County, C… 2452097 Male All ages Hispanic
## 7 06037 Los Angeles County, C… 5123623 Female All ages Both Hispanic …
## 8 06037 Los Angeles County, C… 2660433 Female All ages Non-Hispanic
## 9 06037 Los Angeles County, C… 2463190 Female All ages Hispanic
## 10 06037 Los Angeles County, C… 603555 Both sex… Age 0 to 4 y… Both Hispanic …
## # … with 200 more rowsWith some additional data wrangling, the returned format facilitates analysis and visualization. For example, we can compare population pyramids for Hispanic and non-Hispanic populations in Los Angeles County:
compare <- filter(la_age_hisp, str_detect(AGEGROUP, "^Age"), HISP != "Both Hispanic Origins", SEX != "Both sexes") %>% mutate(value = ifelse(SEX == "Male", -value, value)) ggplot(compare, aes(x = AGEGROUP, y = value, fill = SEX)) + geom_bar(stat = "identity", width = 1) + theme_minimal(base_family = "Roboto") + scale_y_continuous(labels = function(y) paste0(abs(y / 1000), "k")) + scale_x_discrete(labels = function(x) gsub("Age | years", "", x)) + scale_fill_manual(values = c("darkred", "navy")) + coord_flip() + facet_wrap(~HISP) + labs(x = "", y = "2017 Census Bureau population estimate", title = "Population structure by Hispanic origin", subtitle = "Los Angeles County, California", fill = "", caption = "Data source: US Census Bureau population estimates & tidycensus R package")
