Post on 29-Dec-2021
California’s Diverse Demographics and GeographyCitizens Redistricting Commission training
Eric McGhee
August 28, 2020
Outline
2
Sources of data
Demographic trends and patterns
Commission 2011
Outline
3
Sources of data
– Decennial censuses
– Population estimates and projections
– Survey data
– Administrative data and other sources
– Errors in the data
Demographic trends and patterns
Commission 2011
Outline
4
Sources of data
– Decennial censuses
– Population estimates and projections
– Survey data
– Administrative data and other sources
– Errors in the data
Demographic trends and patterns
Commission 2011
Decennial census purpose
5
Why take a census?
– Apportion the House of Representatives
– Determine political districts
– Disburse funds for programs (more than $400 billion in federal funds every year)
– Develop a portrait of our nation
Decennial census goals and methods
6
The 2020 Census
– Goal: Count everyone once, only once, and in the right place
– One person reports for everyone else in the household
– Questionnaire: Just a few questions (name, age, race/ethnicity, gender, own/rent, relationships within household)
– Citizenship question controversy
Outline
7
Sources of data
– Decennial censuses
– Population estimates and projections
– Survey data
– Administrative data and other sources
– Errors in the data
Demographic trends and patterns
Commission 2011
Population estimates and projections
8
Estimates are historical population figures
Projections are future population figures
Produced by the US Census Bureau and the California Department of Finance
Estimates are based on decennial census counts updated with recent administrative data
Projections are based on assumptions about future fertility, mortality, and migration rates
Type of estimates data available
9
Census Bureau Dept. of Finance
Population totals
State X X
Counties X X
Cities (total population only) X X
Components of change
Births X X
Deaths X X
Domestic migration X X
International migration X X
Number and type of housing units X
Population characteristics
Age X X
Gender X X
Ethnicity X X
Latest population estimates have diverged some
10
Source: Department of Finance, U.S. Census Bureau
30,000
32,000
34,000
36,000
38,000
40,000
42,000
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Po
pu
lati
on
(1000s)
DOF
Census Bureau
Projections for California can diverge a lot
11
30,000
35,000
40,000
45,000
50,000
2010 2015 2020 2025 2030 2035 2040
Po
pu
lati
on
(1000s)
USC 2012
DOF 2020
UVA 2018
Outline
12
Sources of data
– Decennial censuses
– Population estimates and projections
– Survey data
– Administrative data and other sources
– Errors in the data
Demographic trends and patterns
Commission 2011
Two primary surveys of the U.S. population
13
Both surveys conducted by the Census Bureau
Current Population Survey
– Monthly survey
– Focus on labor market
American Community Survey (ACS)
What is the ACS?
14
Monthly survey conducted by the Census Bureau
Annually samples about 3 million households
Items covered are similar to those of the long-form questionnaire of the 2000 decennial census
Replaced the long form of the census starting in 2010
ACS: Topics Covered
15
Demographic characteristics
Income and employment
Transportation
Education
Origins and languages
Migration
Disability and caregivers
Housing: Physical characteristics
Housing: Financial characteristics
Advantages of the ACS
16
Large sample relative to the Current Population Survey
– ~3 million (~250K / mo) versus 60,000 households
Timely data relative to the decennial census
Lots of topics covered—great portrait of the nation on many dimensions
Limitations of the ACS
17
Not a count of the population
Small sample relative to the decennial census
– Census long-form went to one in six households
– ACS goes to one in forty
A moving average rather than a point in time
Estimates for census tracts and block groups will be based on five year periods
Can’t be used for redistricting
Estimates still pegged to the decennial census
Outline
18
Sources of data
– Decennial censuses
– Population estimates and projections
– Survey data
– Administrative data and other sources
– Errors in the data
Demographic trends and patterns
Commission 2011
Administrative and other sources of demographic and housing data
19
California Statewide Database (UC Berkeley)
– Voter registration
– Election outcomes
– Maps and mapping resources
California Department of Education
– School demographics
– School test scores
California Employment Development Department
– Unemployment rates
– Occupations
Private sources
Census citizenship data from administrative records
20
Intend to produce full count
– Will come with the redistricting file
Based on matches to administrative records (SS, immigration)
For redistricting?
– Ambiguity from U.S. Supreme Court
– California constitution much less ambiguous: “population equality” and “equal population”
Outline
21
Sources of data
– Decennial censuses
– Population estimates and projections
– Survey data
– Administrative data and other sources
– Errors in the data
Demographic trends and patterns
Commission 2011
California tends to have high net undercount rates
22
1990
– CA: -2.7%
– US: -1.6%
2000
– CA: -0.1% (one of only 10 states)
– US: +0.5%
2010
– CA: -0.26%
– US: +0.01%
Undercounts vary by county
23
2.31.9
2.6
1
1.9
3
1.2
3.5
0.7
3
0.9 0.8
1.6 1.7
0.5
5.7
2
10.1
3.1
10.2
4.8
1.5 1.5
3
1.3
2
3.1
0.9
1.9
1.2
1.81.4
2.5
1.7
0.3
6.4
0
2
4
6
8
10
12
2010 N
et
un
de
rco
un
t (x
1000)
Source: US Census Bureau
Concerns about a 2020 Census undercount:Pre-pandemic
24
Funding challenges
First-time Internet survey
More aggressive administrative matching
General distrust that depresses response rates
Non-citizen distrust
Concerns about a 2020 Census undercount:Post-pandemic
25
Crowding out of census news
Cancellation/delay of in-person events and enumerations
Displacement due to pandemic (what is the “right place”?)
Difficulty finding enumerators to go into the field
Distance from official census day (April 1)
Tight timeline
– Limited in-field quality checks
– Compressed timeline for post-field data fixes
Some parts of California more vulnerable to undercount
26Source: US Census Bureau
What should we do about a bad census?
27
Quality metrics
– Department of Finance estimates
– Post-Enumeration Survey (PES) and demographic analysis (DA)
– Type of count conducted (Total only? Proxy?)
Detailed enough?
Timely enough?
Outline
28
Sources of data
– Decennial censuses
– Population estimates and projections
– Survey data
– Administrative data and other sources
– Errors in the data
Demographic trends and patterns
Commission 2011
Outline
29
Sources of data
Demographic trends and patterns
Commission 2011
Outline
30
Sources of data
Demographic trends and patterns
Commission 2011
Outline
31
Sources of data
Demographic trends and patterns
– Overall change
– Racial and ethnic change
– Geographic change
Commission 2011
Outline
32
Sources of data
Demographic trends and patterns
– Overall change
– Racial and ethnic change
– Geographic change
Commission 2011
California has a large and growing population
33
Populations in thousands 1900-2019
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Comparisons of Population Change 1950=100
34
100
150
200
250
300
350
400
450
500
1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 2006 2010 2014 2018
Mexico California United States
Source: US Census Bureau
Outline
35
Sources of data
Demographic trends and patterns
– Overall change
– Racial and ethnic change
– Geographic change
Commission 2011
California Population by Race/Ethnicity1970-2018
36
Source: United States Census Bureau, decennial censuses and American Community Survey
78
67
57
47 42
37
12
19
26
30 37
38
3 7 10
12 13
14
7 8 7
6 6
6
0
20
40
60
80
100
1970 1980 1990 2000 2010 2018
Mulitracial
African American
Asian/Other
Hispanic
White
Ethnic Majorities by Census Tract, 2010
37
Los Angeles Area
San Francisco Bay Area
50% or greater Native American
50% or greater African American
50% or greater Asian
50% or greater Hispanic
50% or greater non-Hispanic White
Percent Foreign Born Population 1880-2018
38
0%
10%
20%
30%
40%
1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2018
Perc
en
t re
sid
en
ts w
ho
are
fo
reig
n b
orn
California Rest of the United States
Latin America is the Leading Source of Immigrants
39
Source: 2018 American Community Survey
Latin America 5,302,000 (50%)
Asia 4,222,000 (40%)
Europe 684,000 (6%)
Africa 202,000 (2%)
Canada 130,000 (1%)
Oceania 85,000 (1%)
Immigrants Come to California from Dozens of Countries
40
Mexico Iran Thailand Pakistan Cuba Burma Belize Jordan
China Taiwan Russia Iraq Argentina Romania Ireland Saudi Arabia
Philippines Canada Nicaragua Colombia Israel Ethiopia Tukey Sweden
Vietnam Japan Honduras Indonesia Lebanon Nigeria Chile Nepal
India Hong Kong England Brazil Afghanistan Ecuador Malaysia Costa Rica
El Salvador Germany Cambodia France Italy Poland Spain Greece
Korea Peru Ukraine Egypt Portugal Australia Bangladesh Sri Lanka
Guatemala Armenia Laos Fiji Syria Netherlands Jamaica Hungary
Latinos have become the single largest ethnic group
41Source: CA Department of Finance
0
5
10
15
20
25
30
35
40
45
2010 2015 2020 2025 2030 2035 2040
White
Latino
AsianAmericanAfricanAmerican
California Population by Age, 2018
42
Source: American Community Survey
0
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
3,500,000
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85+
Younger Californians are much more diverse
43Source: American Community Survey
0%
20%
40%
60%
80%
100%
Under 5years
5 to 9years
10 to 14years
15 to 17years
18 and19 years
20 to 24years
25 to 29years
30 to 34years
35 to 44years
45 to 54years
55 to 64years
65 to 74years
75 to 84years
85 yearsand over
Other
Multiracial
African American
Asian
Latino
White
California’s diversity is not represented among its voters
44
58
19
13
6
3
Likely voters
21
57
18
3
1
Not registered to vote
White
Latino
Asian
Black
Other
Source: PPIC Statewide Survey
Outline
45
Sources of data
Demographic trends and patterns
– Overall change
– Racial and ethnic change
– Geographic change
Commission 2011
Population deviations: US Congressional districts
46
Population deviation
-1% or less
0
1% or greater
Population deviations: California Senate districts
47
Population deviation
-1% or less
0
1% or greater
Population deviations: California Assembly districts
48
Population deviation
-1% or less
0
1% or greater
Population deviations are smaller so far this cycle
49
Source: American Community Survey
Outline
50
Sources of data
Demographic trends and patterns
– Overall change
– Racial and ethnic change
– Geographic change
Commission 2011
Outline
51
Sources of data
Demographic trends and patterns
Commission 2011
Outline
52
Sources of data
Demographic trends and patterns
Commission 2011
Outline
53
Sources of data
Demographic trends and patterns
Commission 2011
– Mandated goals
– Aspirational goals
Outline
54
Sources of data
Demographic trends and patterns
Commission 2011
– Mandated goals
– Aspirational goals
The CRC districts had to meet several goals
55
Equal population
Compliant with Voting Rights Act
Geographically contiguous, compact, and respectful of communities with common interests
Nested: two state assembly districts in each state senate district
Not skewed by party or incumbent favoritism
VRA: new plans improved Latino, Asian-American representation
56
2001 Plan 2011 Draft Plan 2011 Final Plan
African-American 0 0 0
Latino 18 19 26
Asian-American 0 0 1
Majority-minority districts by plan
Cities: modest decline in split cities
57
2001 Plan 2011 Draft Plan 2011 Final Plan
Assembly 11% 8% 8%
Senate 4% 6% 4%
Congress 6% 12% 9%
Share of cities split between districts
Counties: decline in split counties for Senate
58
2001 Plan 2011 Draft Plan 2011 Final Plan
Assembly 27 27 28
Senate 25 26 20
Congress 24 27 25
Number of counties split between districts
Compactness: districts became far less convoluted
59
2001 Plan 2011 Draft Plan 2011 Final Plan
Assembly 0.20 0.25 0.26
Senate 0.12 0.21 0.23
Congress 0.13 0.23 0.23
Average district compactness (Polsby-Popper)
Nesting: some remaining improvement after dramatic change
60
2001 Plan 2011 Draft Plan 2011 Final Plan
Average number of
Assembly districts
per Senate district
6.35 2.95 4.95
Outline
61
Sources of data
Demographic trends and patterns
Commission 2011
– Mandated goals
– Aspirational goals
Fair and competitive plans were hoped for but not required
62
Fairness to the major parties
– No large gaps between the overall number of votes and seats won
Competitive races in most or all districts
– 45%–55% vote share for each major-party candidate
Partisan fairness: Efficiency gap trends over time are noisy
63
Partisan fairness: Efficiency gap trends over time are noisy
64
Partisan fairness: Efficiency gap trends over time are noisy
65
Competition: CRC assembly districts are consistently more competitive than the districts drawn in 2001
66
Competition: CRC senate districts are consistently more competitive
67
Competition: CRC congressional districts are consistently more competitive
68
California’s Diverse Demographics and GeographyCitizens Redistricting Commission training
Eric McGhee
August 28, 2020
Notes on the use of these slides
70
These slides were created to accompany a presentation. They do not include full documentation of sources, data samples, methods, and interpretations. To avoid misinterpretations, please contact:
Eric McGhee (mcghee@ppic.org; 415-291-4439)
Thank you for your interest in this work.