It's the Demographics, Stupid!
It’s the Demographics, Stupid! - this is an oft repeated phrase, used to explain any number of things from the gentrification of inner cities, the opioid crises, the state of public infrastructure to, of course, politics, from city councils to the oval office. The demographic make-up of a region is, no doubt, the driver of many civic and socio-economic changes in the region. In other words, understanding the underlying demographics is imperative to getting a grip on the other higher-level changes that a region is experiencing. It is with these thoughts in mind that I decided to look up the demographics data for the San Diego county.
As it is with any data having to do with the US population, the US Census Bureau and the data collected through its survey of US residents, the American Community Survey is the go-to source for all things demographics.
The ACS publishes population estimates in 1, 3 and 5-year time-frames. Needless to say, the more number of years of sample data that an estimate is based on, the more accurate it is. Samples are collected for approximately 10% of the US population year-round. Since smaller samples have larger margins of error, the 1 year data, with fewer independent samples, is not accurate enough to publish estimates for areas with under 65K in population. For 3-year estimates this number drops down to 20K and with the 5-year estimates this limitation no longer exists. On the flip side, 5-year estimates are also not the most current.
The demographic data visualized here is from the 2016 5-year estimate. Data was downloaded and visualized for each of the 18 cities that make up the San Diego county. This of course leaves out populations from the unincorporated regions of the county. Nevertheless, it still accounts for a majority of the county’s population.
From the above graphic it is quite clear that the county has a well-balanced sex ratio across all of its cities. Given that gender is currently only expressed in binary (Male/Female) terms within the ACS dataset, this visualization is also representative of the population sizes of the cities, with the City of San Diego surpassing others by a significant margin and Del Mar coming in last.
A comparison of the racial composition across cities indicates that whites are the majority group in all but a handful of cities. Hispanics are the second largest group. It is also note-worthy that nearly all cities are home to atleast 4 or more racial groups.
We can also see that the county is fairly young, with seniors accounting of less than a fifth of the population and children under 18 accounting for more than a fifth of the population across the county.
This final visualization, created as a Tableau Dashboard, provides an overview of the county-wide demographics (aggregated across all cities) at a glance.
Additional Analysis
For additional analysis, the Python code used to wrangle the data, and the Tableau workbook containing the visualizations take a look at the notebook here.
ANALYSIS Python VISUALIZATION Tableau FORMAT json ACCESS API