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Data Documentation for US Census Bureau's Population Estimate Data

This document outlines the process for acquiring demographic data from the United States Census Bureau’s Population and Housing Estimates. It details the approach of the Southern Regional Drug Data Research Centers (SR-DDRC, or just DDRC) to extracting, transforming, and loading (ETL) the data into Microsoft SQL Server, as well as the creation of the dataset’s data dictionary (in development). This guide is intended for data analysts and researchers interested in replicating the SR-DDRC’s process or using the data acquired by the SR-DDRC.

1. Overview of the US Census Bureau’s Population and Housing Estimates

The US Census Bureau is collects critical data about the U.S. population and economy. Every 10 years, the Census Bureau conducts a nationwide census to gather comprehensive information on the population size, demographics, and economic conditions across the country.

Alongside the decennial census, the Census Bureau produces annual population estimates, which provide valuable insights into population changes in the years between censuses. These yearly estimates are derived from the most recent 10-year census data and are adjusted using the latest governmental records on births, deaths, and migration. Birth and death data is sourced from the National Center for Health Statistics (NCHS), while migration data is provided by the Office of Immigration Statistics (OIS). Although population estimates may not perfectly reflect real-time changes, they are considered the most accurate available snapshot of the U.S. population between decennial censuses.

2. US Census Bureau’s Population and Housing Estimates Dataset

This dataset provides annual population and housing estimates, along with data on births, deaths, and migration, broken down by state and county. The data also includes the base population total for each stratification used in calculating estimates.

3. US Census Bureau’s Population and Housing Estimates Data Acquisition

This section describes US Census Bureau’s FTP2 site and the SR-DDRC's process for acquiring the US Census Bureau’s Population and Housing Estimates data.

3.1 US Census Bureau’s Population and Housing Estimates Data Access Options

The U.S. Census Bureau offers population and housing estimate data for download through its FTP2 site, where users can select from different datasets. After selecting “popest/”, users can select “datasets/” or “tables/” for different data vintages, each covering specific year ranges. If users select “datasets/”, they will have access to the more recent data files. Files downloaded from the FTP2 site are organized by vintage and provided as CSV (comma separated values) files.

Users can also access historical estimate files for certain vintages through the US Census Bureau application programming interface (API). However, the latest estimates are currently unavailable via the API.

3.2 US Census Bureau’s Population and Housing Estimates Data Download Process

From the FTP2 site, the SR-DDRC downloaded annual population and housing estimates for the nation, covering state and county levels from 2010 to 2023. The following steps were performed in order:

  1. Selected “popest/”
  2. Selected “datasets/”
  3. Selected desired vintage, example: 2010-2020/, 2020-2023/
  4. Selected “counties/”
  5. Selected “totals/”
  6. Selected respective “alldata.csv”, example co-est2020-alldata.csv

4. ETL Process

Coming Soon

5. DDRC Data Dictionary

The SR-DDRC used information published by the US Census Bureau for the Population and Housing Estimates, including documents on methodology, to create the data dictionary for the exported files. The SR-DDRC data dictionary for the US Census Bureau’s Population Estimate data is currently in development and will be published in a forthcoming release.

We recommend that users still review and reference documentation provided by US Census Bureau for the Population and Housing Estimates for the most detailed and up-to-date information.

If you have additional questions about this dataset, please contact us at info@srddrc.com