Last week, the Census Bureau released the latest 5-year estimates for the American Community Survey for 2016-2020. This latest dataset uses the new 2020 census geography, which means if you’re focused on using the latest data, you can finally move away from the 2010-based geography which had been used for the ACS from 2010 to 2019 (with some caveats: 2020 ZCTAs won’t be utilized until the 2021 ACS, and 2020 PUMAs until 2022). As always, mappers have a choice between the TIGER Line files that depict the precise boundaries, or the generalized cartographic boundary files with smoothed lines and large sections of coastal water bodies removed to depict land areas. The 2016-2020 ACS data is available via data.census.gov and the ACS API.
This release is over 3 months late (compared to normal), and there was some speculation as to whether it would be released at all. The pandemic (chief among several other disruptive events) hampered 2020 decennial census and ACS operations. The 1-year 2020 ACS numbers were released over 2 months later than usual, in late November 2021, and were labeled as an experimental release. Instead of the usual 1,500 plus tables in 40 subject areas for all geographic areas with over 65,000 people, only 54 tables were released for the 50 states plus DC. This release is only available from the experimental tables page and is not being published via data.census.gov.
What happened? The details were published in a working paper, but in summary fewer addresses were sampled and the normal mail out and follow-up procedures were disrupted (pg 8). The overall sample size fell from 3.5 to 2.9 million addresses due to reduced mailing between April and June 2020 (pg 18), and total interviews fell from 2 million to 1.4 million with most of the reductions occurring in spring and summer (pg 18). The overall housing unit response rate for 2020 was 71%, down from 86% in 2019 and 92% in 2018 (pg 20). The response rate for the group quarters population fell from 91% in 2019 to 47% in 2020 (pg 21). Responses were differential, varying by time period (with the lowest rates during the peak pandemic months) and geography. Of the 818 counties that meet the 65k threshold, response rates in some were below 50% (pg 21). The data contained a large degree of non-response bias, where people who did respond to the survey had significantly different social, economic and housing characteristics from those who didn’t. As a consequence of all of this, margins of error for the data increased by 20 to 30% over normal (pg 18).
Thus, 2020 will represent a hole in the ACS estimates series. The Bureau made adjustments to weighting mechanisms to produce the experimental 1-year estimates, but is generally advising policy makers and researchers who normally use this series to choose alternatives: either the 1-year 2019 ACS, or the 5-year 2016-2020 ACS. The Bureau was able to make adjustments to produce satisfactory 5-year estimates to reduce non-response bias, and the 5-year pool of samples is balanced somewhat by having at least 4 years of good data.
The Population Estimates Program has also released its latest series of vintage 2021 estimates for counties and metropolitan areas. This dataset gives us a pretty sharp view of how the pandemic affected the nation’s population. Approximately 73% of all counties experienced natural decrease in 2021 (between July 1st 2020 and 2021), where the number of deaths outnumbered births. In contrast, 56% of counties had natural decrease in 2020 and 46% in 2019. Declining birth rates and increasing death rates are long term trends, but COVID-19 magnified them, given the large number of excess deaths on one hand and families postponing child birth due to the virus on the other hand. Net foreign migration continued its years-long decline, but net domestic migration increased in a number of places, reflecting pandemic moves. Medium to small counties benefited most, as did large counties in the Sunbelt and Mountain West. The biggest losers in overall population were counties in California (Los Angeles, San Francisco, and Alameda), Cook County (Chicago), and the counties that constitute the boroughs of NYC.
In late summer and early fall I was hammering out the draft for an ALA Tech Report on using census data for research (slated for release early 2022). The earliest 2020 census figures have been released and there are several issues surrounding this, so I’ll provide a summary of what’s happening here. Throughout this post I link to Census Bureau data sources, news bulletins, and summaries of trends, as well as analysis on population trends from Bill Frey at Brookings and reporting from Hansi Lo Wang and his colleagues at NPR.
Count Result and Reapportionment Numbers
The re-apportionment results were released back in April 2020, which provided the population totals for the US and each of the states that are used to reallocate seats in Congress. This data is typically released at the end of December of the census year, but the COVID-19 pandemic and political interference in census operations disrupted the count and pushed all the deadlines back.
Despite these disruptions, the good news is that the self-response rate, which is the percentage of households who submit the form on their own without any prompting from the Census Bureau, was 67%, which is on par with the 2010 census. This was the first decennial census where the form could be submitted online, and of the self-responders 80% chose to submit via the internet as opposed to paper or telephone. Ultimately, the Bureau said it reached over 99% of all addresses in its master address file through self-response and non-response follow-ups.
The apportionment results showed that the population of the US grew from approximately 309 million in 2010 to 331 million in 2020, a growth rate of 7.35%. This is the lowest rate of population growth since the 1940 census that followed the Great Depression. Three states lost population (West Virginia, Mississippi, and Illinois), which is the highest number since the 1980 census. The US territory of Puerto Rico lost almost twelve percent of its population. Population growth continues to be stronger in the West and South relative to the Northeast and Midwest, and the fastest growing states are in the Mountain West.
Public Redistricting Data
The first detailed population statistics were released as part of the redistricting data file, PL 94-171. Data in this series is published down to the block level, the smallest geography available, so that states can redraw congressional and other voting districts based on population change. Normally released at the end of March, this data was released in August 2021. This is a small package that contains the following six tables:
P1. Race (includes total population count)
P2. Hispanic or Latino, and Not Hispanic or Latino by Race
P3. Race for the Population 18 Years and Over
P4. Hispanic or Latino, and Not Hispanic or Latino by Race for the Population 18 Years and Over
P5. Group Quarters Population by Major Group Quarters Type
H1. Occupancy Status (includes total housing units)
The redistricting files illustrate the increasing diversity of the United States. The number of people identifying as two or more races has grown from 2.9% of the total population in 2010 to 10.2% in 2020. Hispanics and Latinos continue to be the fastest growing population group, followed by Asians. The White population actually shrank for the first time in the nation’s history, but as NPR reporter Hansi-Lo Wang and his colleagues illustrate this interpretation depends on how one measures race; as race alone (people of a single race) or persons of any race (who selected white and another race), and whether or not Hispanic-whites are included with non-Hispanic whites (as Hispanic / Latino is not a race, but is counted separately as an ethnicity, and most Hispanics identify their race as White or Other). The Census Bureau has also provided summaries using the different definitions. Other findings: the nation is becoming progressively older, and urban areas outpaced rural ones in population growth. Half of the counties in the US lost population between 2010 and 2020, mostly in rural areas.
2020 Demographic and Housing Characteristics and the ACS
There still isn’t a published timeline for the release of the full results in the Demographic and Housing Characteristics File (DHC – known as Summary File 1 in previous censuses, I’m not sure if the DHC moniker is replacing the SF1 title or not). There are hints that this file is going to be much smaller in terms of the number of tables, and more limited in geographic detail compared to the 2010 census. Over the past few years there’s been a lot of discussion about the new differential privacy mechanisms, which will be used to inject noise into the data. The Census Bureau deemed this necessary for protecting people’s privacy, as increased computing power and access to third party datasets have made it possible to reverse engineer the summary census data to generate information on individuals.
What has not been as widely discussed is that many tables will simply not be published, or will only be summarized down to the county-level, also for the purpose of protecting privacy. The Census Bureau has invited the public to provide feedback on the new products and has published a spreadsheet crosswalking products from 2010 and 2020. IPUMS also released a preliminary list of tables that could be cut or reduced in specificity (derived from the crosswalk), which I’m republishing at the bottom of this post. This is still preliminary, but if all these changes are made it would drastically reduce the scope and specificity of the decennial census.
And then… there is the 2020 American Community Survey. Due to COVID-19 the response rates to the ACS were one-third lower than normal. As such, the sample is not large or reliable enough to publish the 1-year estimate data, which is typically released in September. Instead, the Census will publish a smaller series of experimental tables for a more limited range of geographies at the end of November 2021. There is still no news regarding what will happen with the 5-year estimate series that is typically released in December.
Needless to say, there’s no shortage of uncertainty regarding census data in 2020.
Tables in 2010 Summary File 1 that Would Have Less Geographic Detail in 2020(Proposed)
Proposed 2020 Lowest Level of Geography
2010 Lowest Level of Geography
Hispanic or Latino Origin of Householder by Race of Householder
Household Size by Household Type by Presence of Own Children
Household Type by Age of Householder
Households by Presence of People 60 Years and Over by Household Type
Households by Presence of People 60 Years and Over, Household Size, and Household Type
Households by Presence of People 75 Years and Over, Household Size, and Household Type
Household Type by Household Size
Household Type by Household Size by Race of Householder
Relationship by Age for the Population Under 18 Years
Household Type by Relationship for the Population 65 Years and Over
Household Type by Relationship for the Population 65 Years and Over by Race
Family Type by Presence and Age of Own Children
Family Type by Presence and Age of Own Children by Race of Householder
Age of Grandchildren Under 18 Years Living with A Grandparent Householder
Household Type by Relationship by Race
Average Household Size by Age
To be determined
Household Type for the Population in Households
To be determined
Household Type by Relationship for the Population Under 18 Years
To be determined
Population in Families by Age
To be determined
Average Family Size by Age
To be determined
Family Type and Age for Own Children Under 18 Years
To be determined
Total Population in Occupied Housing Units by Tenure
To be determined
Average Household Size of Occupied Housing Units by Tenure
To be determined
Sex by Age for the Population in Households
Sex by Age for the Population in Households by Race
Presence of Multigenerational Households
Presence of Multigenerational Households by Race of Householder
Coupled Households by Type
Nonfamily Households by Sex of Householder by Living Alone by Age of Householder
Group Quarters Population by Sex by Age by Group Quarters Type
Tables in 2010 Summary File 1 That Would Be Eliminated in 2020(Proposed)
Population in Households by Age by Race of Householder
Average Household Size by Age by Race of Householder
Households by Age of Householder by Household Type by Presence of Related Children
Households by Presence of Nonrelatives
Household Type by Relationship for the Population Under 18 Years by Race
Household Type for the Population Under 18 Years in Households (Excluding Householders, Spouses, and Unmarried Partners)
Families by Race of Householder*
Population in Families by Age by Race of Householder
Average Family Size by Age by Race of Householder
Family Type by Presence and Age of Related Children
Family Type by Presence and Age of Related Children by Race of Householder
Group Quarters Population by Major Group Quarters Type*
Allocation of Population Items
Allocation of Race
Allocation of Hispanic or Latino Origin
Allocation of Sex
Allocation of Age
Allocation of Relationship
Allocation of Population Items for the Population in Group Quarters
American Indian and Alaska Native Alone with One Tribe Reported for Selected Tribes
American Indian and Alaska Native Alone with One or More Tribes Reported for Selected Tribes
American Indian and Alaska Native Alone or in Combination with One or More Other Races and with One or More Tribes Reported for Selected Tribes
American Indian and Alaska Native Alone or in Combination with One or More Other Races
Asian Alone with One Asian Category for Selected Groups
Asian Alone with One or More Asian Categories for Selected Groups
Asian Alone or in Combination with One or More Other Races, and with One or More Asian Categories for Selected Groups
Native Hawaiian and Other Pacific Islander Alone with One Native Hawaiian and Other Pacific Islander Category for Selected Groups
Native Hawaiian and Other Pacific Islander Alone with One or More Native Hawaiian and Other Pacific Islander Categories for Selected Groups
Native Hawaiian and Other Pacific Islander Alone or in Combination with One or More Races, and with One or More Native Hawaiian and Other Pacific Islander Categories for Selected Groups
Hispanic or Latino by Specific Origin
Sex by Single Year of Age by Race
Household Type by Number of Children Under 18 (Excluding Householders, Spouses, and Unmarried Partners)
Presence of Unmarried Partner of Householder by Household Type for the Population Under 18 Years in Households (Excluding Householders, Spouses, and Unmarried Partners)
Nonrelatives by Household Type
Nonrelatives by Household Type by Race
Group Quarters Population by Major Group Quarters Type by Race
Group Quarters Population by Sex by Major Group Quarters Type for the Population 18 Years and Over by Race
Total Races Tallied for Householders
Hispanic or Latino Origin of Householders by Total Races Tallied
Total Population in Occupied Housing Units by Tenure by Race of Householder
Average Household Size of Occupied Housing Units by Tenure
Average Household Size of Occupied Housing Units by Tenure by Race of Householder
Occupied Housing Units Substituted
Allocation of Vacancy Status
Allocation of Tenure
Tenure by Presence and Age of Related Children
* Counts for these tables are available in other proposed DHC tables. For example, the count of families is available in the Household Type table, which will be available at the block level in the 2020 DHC.
Upon receiving a reminder from WordPress that it’s time to renew my subscription, I looked back and realized I’ve been pretty consistent over the years. Since rebooting this blog in Sept 2017, with few exceptions I’ve fulfilled my goal to write one post per month.
Unfortunately, due to professional and personal constraints I’m going to have to break my streak and put posting on pause for a while. Hopefully I can return to writing in the fall. Until then, enjoy the rest of summer.
I just released a new edition of my introductory QGIS manual for QGIS 3.16 Hannover (the current long term release), and as always I’m providing it under Creative Commons for classroom use and self-directed learning. I’ve also updated my QGIS FAQs handout, which is useful for new folks as a quick reference. This material will eventually move to a Brown University website, but when that happens I’ll still hold on to my page and will link to the new spot. I’m also leaving the previous version of the tutorial written for QGIS 3.10 A Coruna up alongside it, but will pull that down when the fall semester begins.
The new edition has a new title. When I first wrote Introduction to GIS Using Open Source Software, free and open source (FOSS) GIS was a novelty in higher ed. QGIS was a lot simpler, and I had to pull in several different tools to accomplish basic tasks like CRS transformations and calculating natural breaks. Ten years later, many university libraries and labs with GIS services either reference or support QGIS, and the package is infinitely more robust. So a name change to simply Introduction to GIS with QGIS seemed overdue.
My move from Baruch CUNY to Brown prompted me to make several revisions in this version. The biggest change was swapping the NYC-based business site selection example with a Rhode Island-based public policy one in chapters 2 and 3. The goal of the new hypothetical example is to identify public libraries in RI that meet certain criteria that would qualify them to receive funding for after school programs for K-12 public school students (replacing the example of finding an optimal location for a new coffee shop in NYC). In rethinking the examples I endeavored to introduce the same core concepts: attribute table joins, plotting coordinates, and geoprocessing. In this version I do a better job of illustrating and differentiating between creating subsets of features by: selecting by attributes and location, filtering (a new addition), and deleting features. I also managed to add spatial joins and calculated fields to the mix.
Changes to chapter 4 (coordinate reference systems and thematic mapping) were modest; I swapped out the 2016 voter participation data with 2020 data. I slimmed down Chapter 5 on data sources and tutorials, but added an appendix that lists web mapping services that you can add as base maps. Some material was shuffled between chapters, and all in all I cut seven pages from the document to slim it down a bit.
As always, there were minor modifications to be made due to changes between software versions. There were two significant changes. First, QGIS no longer supports 32 bit operating systems for Windows; it’s 64 bit or nothing, but that seems to be fairly common these days. Second, the Windows installer file is much bigger (and thus slower to download), but it helps insure that all dependencies are there. Otherwise, the differences between 3.16 and 3.10 are not that great, at least for the basic material I cover. In the past there was occasionally a lack of consistency regarding basic features and terminology that you’d think would be well settled, but thankfully things are pretty stable this time around.
If you have any feedback or spot errors feel free to let me know. I imagine I’ll be treading this ground again after the next long term release take’s 3.16’s place in Feb / Mar 2022. For the sake of stability I always stick with the long term release and forego the latest ones; if you’re going to use this tutorial I’d recommend downloading the LTR version and not the latest one.
I’m serving as a co-editor for a special issue for the Journal of Maps entitled “Celebrating the Census“. The Journal of Maps is an open access, peer reviewed journal published by the Taylor & Francis Group. The journal is distinct in that all articles feature maps and spatial diagrams as the focal point for studying geographic phenomena from both a physical / environmental and social science perspective.
Here’s the official synopsis for this census-themed special issue:
We invite contributions to a special issue of the Journal of Maps focused upon the evolving character and cartographic opportunities offered by traditional census statistics and the impact of transitioning from these sources of population data at a range of spatial scales into a new era of big data assembly. In so doing, the special issue marks two important events taking place in the UK during 2021 in the history of British Censuses and seeks contributions that reflect the past transition of population data cartography through the digital era of the last 50 years and anticipates its transformation into the big data era of the foreseeable future.
While the issue marks the 100th anniversary of the UK census, submissions concerning census mapping from around the world are welcome and encouraged in these topic areas, including but not limited to:
Spatial and statistical consistency over time
People on the move
Mapping people through space and time
Mapping morbidity and mortality
Politics and population data
International comparison of demographic mapping
Before and after population mapping using censuses and administrative sources
Population data and mapping human-environmental interaction
I have some news! After 13 1/2 years, January 31, 2021 will be my last day as the Geospatial Data Librarian at Baruch College, City University of New York (CUNY). On February 1, 2021, I will be the new GIS and Data Librarian at Brown University in Providence, Rhode Island!
It’s an exciting opportunity that I’m looking forward to. I will be building geospatial information and data services in the library from the ground up, in concert with many new colleagues. I will be working closely with the Population Studies Training Center (PSTC) and the Spatial Structures in Social Sciences (S4) as well as the Center for Digital Scholarship within the library. Several aspects of the position will be similar, as I will continue to provide research and consultation services, create research guides and tutorials, teach workshops, collect and create datasets, and eventually build and manage a data repository and small lab where we’ll provide services and peer mentor students.
The resources I’ve created at Baruch CUNY will remain accessible, and eventually a new person will take the reins. I have moved the latest materials for the GIS Practicum, my introductory QGIS tutorial and workshop, to this website and I hope to continue updating and maintaining this resource. There are a lot of people throughout CUNY that I’m going to miss, at: the Newman Library, the CUNY Institute for Demographic Research, the Weissman Center for International Business, the Marxe School, Baruch’s Journalism Department, the Geography Department at Lehman College, the Digital Humanities program and the CUNY Mapping Service at the CUNY Graduate Center, and many others.
I will continue writing posts and sharing tips and resources here based on my new adventures at Brown, but may need a little break as I transition… stay tuned!