Workflow with tidycensus"

In zctaCrosswalk: Crosswalk Between 2020 Census ZIP Code Tabulation Areas (ZCTAs), States and Counties

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

library(zctaCrosswalk)
library(tidycensus)
library(dplyr)

zctaCrosswalk was designed to work well with the tidycensus package. tidycensus is currently the most popular way to access Census data in R. Here is an example of using it to get Median Household Income on all ZCTAs in the US:

zcta_income = get_acs(
  geography = "zcta",
  variables = "B19013_001",
  year      = 2021)

head(zcta_income)

Note that ?get_acs returns data for all ZCTAs in the US. It does not provide an option to get data on ZCTAs by State or County. And the dataframe it returns does not provide enough metadata to allow you to do this subselection yourself.

A primary motivation for creating the zctaCrosswalk package was to support this type of analysis. Note that ?get_acs returns the ZCTA in a column called GEOID. We can combine this fact with ?dplyr::filter, ?get_zctas_by_county and ?get_zctas_by_state to subset to any states or counties we choose.

Here we filter zcta_income to ZCTAs in San Francisco County, California:

nrow(zcta_income) 

sf_zcta_income = zcta_income |>
  dplyr::filter(GEOID %in% get_zctas_by_county("06075"))

nrow(sf_zcta_income)
head(sf_zcta_income)

Mapping the Result

A primary motivation in creating this workflow (and indeed, this package) was to create demographic maps at the ZCTA level for selected states and counties. If this interests you as well, I encourage you to copy the below code into R and view the output yourself. (Unfortunately, R package vignettes do not seem to handle map output from the mapview package well). This is a powerful and elegant pattern for visualizing ZCTA demographics in R:

library(zctaCrosswalk)
library(tidycensus)
library(dplyr)
library(mapview)

all_zctas = get_acs(
  geography = "zcta",
  variables = "B19013_001",
  year      = 2021,
  geometry  = TRUE)

filtered_zctas = filter(all_zctas, GEOID %in% get_zctas_by_county(6075))

mapview(filtered_zctas, zcol = "estimate")

zctaCrosswalk documentation built on April 19, 2023, 5:08 p.m.