BOS Agenda Date :Septeinber 27, 2005

County of Santa Clara
Department of Planning and Development
Planning Office

PLN02 092705

Prepared by: Steven Golden
Planner III

Reviewed by: Jody Hall Esser
Interim Director of

Planning and
Development
DATE:

September 27, 2005

TO:

Board of Supervisors

FROM:

Jody Hall Esser
Interim Director of Planning and Development
SUBJECT:

Report back on referral regarding U.S. Census infonnation for people in poverty
by Supervisorial District

RECOMMENDED ACTION

Under advisement from June 21,2005 (Item No. 26): Accept report relating to people in

poverty data estimated from the U.S. Census with a particular focus on children, seniors, and
families in poverty.
ETSCAT. TMPTTCATTONS

Board of Supervisors: Donald F. Gage, Blanca Alvarado, Pete McHugh,Jim Beall, Liz Kniss
Coun^/ Executive; Peter Kutras Jr.

1

BOS Agenda Date :September 27. 2005

No impact to the General Fund as a result of this action.
CONTRACT HISTORY

Not applicable.
REASONS FOR RECOMMENDATION

On June 21, 2005 the Board of Supervisors directed administration to develop poverty data by

supervisorial district using Census 2000 data. The data was to focus on those individuals in
poverty that may be eligible for certain need-based services including services provided by
the Senior Nutrition Program, First Five Commission, and other need-based family services.
The original request was for Districts Four and Five, however, the request was expanded to
develop the data for all supervisorial districts. On July 28, 2005 an off-agenda memorandum
was sent to the Board of Supervisors (Board) requesting a time extension to the normal 45 day
response period to report back to the Board because of the significant amount of time required
to fulfill the request and other extraneous circumstances. This transmittal is in response to the
Board of Supervisor's request.
BACKGROUND

Subsequent to receipt of the June 21, 2005 directive. District 4 staff offered some clarification
of the Census 2000 data which would best reflect the eligibility criteria for the identified

soeial service programs. Previously, the Planning Office developed a data report for the
Children Seniors, and Families Committee(CSFC)(Attachment 4: February 16, 2005, Item

No. 9)and a similar methodology was used in this report. The main issue in developing
poverty data for supervisorial districts is that the supervisor districts were created by
assembling Census Blocks and the U.S. Census Bureau does not make poverty data available
at this geographic level. The data is available at larger levels of geography and therefore,
supervisor district boundaries are not entirely coincident with these larger geographic areas. It
was determined that some of the Census poverty data is available at the Block Group

geographic level, however, in some cases the supervisor district boundaries split these
geographic areas.

"Estimating Methodology"

The Planning Office used a similar methodology that was developed for the CSFC, however,
Census Block Groups were used in this analysis (Census Tracts were used in the previous

Board of Supervisors: Donald F. Gage, Blanca Alvarado, Pete McHugh,Jim Beall, Liz Kniss
County Executive: Peter Kutras Jr.

2

BOS Agenda Date :Septernber 27, 2005

analysis). The attached September 27, 2005 memorandum (Attachment 1)from Steven
Golden, Associate Planner, describes the "estimating methodology" in more detail.
Summary of Data

The values reported are only an estimation based on the methodology used. It is possible that
the technique used to assign data amongst split Block Groups does not accurately represent
the actual distribution of individuals for each demographic criterion analyzed because there is

immeasurable uncertainty in the level of correlation between total population and each

demographic criterion analyzed. Local characteristics of neighborhoods and communities play
a key role and could have a significant effect on how concentrated or dispersed these
populations are. For these reasons, ranges are also being reported, which reflect the aetual
range of the number of individuals in each supervisorial district based on the data analyzed.
In addition, some of the demographics reported are based on the number of families. Sinee the
Block Groups were split using population data, it is possible that the splitting might result in
different values if the splitting methodology used the proportional number of families rather
than population totals. Beeause of the time restraints, this analysis was not completed.
However, it is believed the differenee would not likely be signifieant.

The number of individuals with income to poverty ratio of of less than 1.99 and families with

family ineome of less than $45,000 are reported to estimate the number of individuals or
families that might be eligible for need-based services. One of the criteria for some
need—based services is having a family income of less than 300% of the federal poverty limit.
This measure is not direetly reported in Census 2000, therefore, the two estimates reported
were used to assist in estimating this measure. The income limit of $45,000 was derived by
calculating the average of the 300% federal poverty limit for a three— and four—person family
and rounded to the nearest ineome level as reported in Census 2000.

For a summary of the estimated dated, see the attached memorandum from Steven Golden,
Associate Planner.

Mapping

In addition to the data summary, the Board requested maps be developed eomparing areas of
poverty using Census geographies to where senior nutrition sites are located and locations

Board of Supervisors; Donald F. Gage, Blanca Alvarado, Pete McHugh,JIrn Beall, Liz Kniss
County Executive: Peter Kutras Jr.

3

BOS Agenda Date :September 27, 2005

where services to children are provided through the First Five Commission. These maps have
been developed and are included as an attachment to this transmittal (Attachments 2 & 3).
CONSEQUENCES OF NEGATTVK ACTION

This report will not be used for the purposed of evaluating services.
STEPS FOLLOWINCx APPROVAL

The Clerk of the Board will file and maintain a copy of this report.
ATTACHMENTS

• Attachment 1: Memorandum from Planning Office

• Attachment 2: Map of Adults 65 Years and Older in Poverty by Block Group with
Senior Nutrition Sites (original map on file with the Clerk of the Board)

• Attachment 3: Map of Children Less Than 5 Years Old in Poverty by Block Group with
First Five Commission Service Locations (original map on file with the Clerk of the
Board)

• Attachment 4: CSFC Transmittal, February 16, 2005, Item 9

Board ofSupervisors: Donald F. Gage, Blanca Alvarado, Pete McHugh,Jim Beall, Liz Kniss
County Executive: Peter Kutras Jr.

4

DATE;

September 27, 2005

TO:

Board of Supervisors

FROM:

Steven Golden,

Planner III, Planning Offiee
RE:

Response to Board Request for Census Data from June 21, 2005

On June 21,2005, the Board of Supervisors requested that poverty related data based on Census
2000 information be developed for Supervisor Districts Four and Five. Subsequently, the

referral was expanded to include all supervisorial districts. This data was to focus on individuals
that may be eligible for need based services with a focus on seniors, children, and families that
may receive assistance through the Senior Nutrition Program or the First Five Commission. The
following memo describes the methodology of estimating the data by supervisorial district.
"Estimating Methodology"

(This is similar to the memo submitted to the Children Seniors and Families Committee on February 16, 2005)

Supervisorial Districts were previously created through the Redistricting Program that occurred

in 2001. These districts were created by assembling Census Blocks and establishing boundaries
coincident with Census Block boundaries. However, the U.S. Census Bureau does not release

poverty based data at the Census Block geographical level. The Board of Supervisors has
requested to use the smallest level of geography possible to report the data by supervisorial
district. Some poverty based data is available at the Census Block Group level. The available

Census data at the Block Group level was used, but not all ofthe 1010 total Block Group
boundaries are coincident with supervisorial district boundaries (i.e. supervisorial districts split a
number of Block Group areas). Consequently, the data had to be estimated using the most
practical and appropriate method available. The derived method follows;

• For those Block Groups that were entirely located in a particular supervisorial district,
100% ofthe data went to that particular district.

• There were a total of69 split Block Groups between two supervisorial districts. There
were 3 categories for estimating data for these Block Groups as follows:
100% of total population - For 24 of these Block Groups, one section ofthe split
Block Group had 100% ofthe total population, therefore 100% ofthe data was
assigned to the supervisorial district containing the population.

>90% of total population - 20 Block Groups were split where >90% ofthe total
population were located in one section of the split Block Group. In these cases,
all of the data was assigned to the Supervisorial District containing the portion of
the Block Group that had >90% ofthe population.

- <90% of total population - 25 Block Groups were split where <90% of the total
population were located in either section ofthe split Block Group. In these cases
the data was assigned to each supervisorial district according to the percentage of
total population for that section of the Block Group.

Data was obtained from Summary File 3(sample population), 2000 Census, U.S. Census Bureau
using the Bureau’s online database, American FactFinder.
Poverty Definition

The Census Bureau uses the federal government's official poverty definition. The Office of

Management and Budget's(OMB's) Directive 14 prescribes this definition as the official poverty
measure for federal agencies to use in their statistical work. The following is from the U.S.
Census Bureau’s website:

How Poverty Status is Determined

The poverty status of families and unrelated individuals in 1999 was determined using 48 thresholds
(inoome cutoffs) arranged in a two dimensional matrix. The matrix consists of family size (from 1
person to 9 or more people) cross-classified by presence and number of family members under 18
years old (from no children present to 8 or more children present). Unrelated individuals and 2-person
families were further differentiated by the age of the reference person (RP)(under 65 years old and 65
years old and over).

To determine a person's poverty status, one compares the person's total family income with the

poverty threshold appropriate for that person's family size and composition (see table below). If the

total income of that person's family is less than the threshold appropriate for that family, then the

person is considered poor, together with every member of his or her family. If a person is not living
with anyone related by birth, marriage, or adoption, then the person's own income is compared with
his or her poverty threshold.

Weighted average thresholds. Even though the official poverty data are based on the 48 thresholds
arranged by family size and number of children within the family, data users often want to get an idea
of the "average" threshold for a given family size. The weighted average thresholds provide that
summary. They are weighted averages because for any given family size, families with a certain
number of children may be more or less common than families with a different number of children. In
other words, among 3-person families, there are more families with two adults and one child than
families with three adults. To get the weighted average threshold for families of a particular size,

multiply each threshold by the number of families for whom that threshold applies; then add up those
products, and divide by the total number of families who are of that family size.

For example, for 3-person families, 1999 weighted thresholds were calculated in the following way using
information from the 2000 Current Population Survey:
Number of
Family type

Threshold

families

5,213

$13,032 = $67,935,816

One child (two adults)

8,208

$13,410 = $110,069,280

Two children (one adult)

2,656

$13,423 = $35,651,488

No children (three adults)

Totals

16,077

$213,656,584

Source: Current Population Survey, March 2000.

Dividing $213,656,584 by 16,077 (the total number of 3-person families) yields $13,290, the weighted
average threshold for 3-person families. Please note that the thresholds are weighted not just by the
number of poor families, but by all families for which the thresholds apply: the thresholds are used to
determine which families are at or above poverty, as well as below poverty.

Individuals for whom poverty status is determined. Poverty status was determined for all people
except institutionalized people, people in military group quarters, people in college dormitories, and
unrelated individuals under 15 years old. These groups also were excluded from the numerator and

denominator when calculating poverty rates. They are considered neither "poor" nor "nonpoor."

Specified poverty levels. For various reasons, the official poverty definition does not satisfy all the
needs of data users. Therefore, some of the data reflect the number of people below different

percentages of the poverty level. These specified poverty levels are obtained by multiplying the official
thresholds by the appropriate factor. For example, the average income cutoff at 125 percent of the
poverty level was $21,286 ($17,029 x 1.25) in 1999 for family of four people.

Poverty Thresholds in 1999 by Size of Family and Number of Related Children Under 18 Years
Old

(Dollars)
r

Related children under 18 years
Weighted
Average

Size of Family Unit
One person
(unrelated
individual)
Under 65

Eight
One

None

Two

Four

Three

Seven

Six

Five

or
more

Threshold

I

8501

8667

8667

7990

7990

years old
i

65 years old

I

and over
I

Two People

10869

Householder

under 65

11214

11156

11483

10075

10070

11440

13290

13032

13410

years old
Householder

65 years old
and over

Three people

1

jl3423

I

Four people

.17029

17184

17465

|l6895

16954

Five people

20127

20723

21024

20380

19882

19578

22727

23835

23930

|23436

22964

22261

25912

127425

27596

[26595

25828

[30673

30944

[29899

29206

[28327

127412

28967

[27006
[30387

[27180

36897

37076

36583

36169

35489

34554

33708

33499

34417

jSix people
[seven people
[Eight people
Nine people

|21845
[24934

!

[2395?

I

32208

or more

Summary of Data

The values reported are only an estimation based on the methodology used. It is possible that the
technique used to assign data amongst split Block Groups does not accurately represent the
actual distribution of individuals for each demographic criterion analyzed because there is

immeasurable uncertainty in the level of correlation between total population and each

demographic criterion analyzed. Local characteristics of neighborhoods and communities play a
key role and could have a significant effect on how concentrated or dispersed these populations
are. For these reasons, ranges are also being reported, which reflect the actual range of the
number of individuals in each supervisorial district based on the data analyzed.

In addition, some ofthe demographics reported are based on the number of families. Since the

Block Groups were split using population data, it is possible that the splitting might result in

different values if the splitting methodology used the proportional number of families rather than
population totals. Because ofthe time restraints, this analysis was not completed. However, it is
believed the difference would not likely be significant.

The number of individuals with income to poverty ratio of <1.99* and families with family
income <$45,000 are reported to estimate the number of individuals or families that might be
eligible for need based services. One ofthe criteria for some need based services is having a
family income <300% of the federal poverty limit. This measure is not directly reported in
Census 2000, therefore, the two estimates reported were used to assist in estimating this measure.
The income limit of $45,000 was derived by calculating the average ofthe 300% federal poverty

limit for a 3- and 4-person family^ and rounded to the nearest income level as reported in Census
2000.

Notes(For all tables):

1. As calculated using the "Estimating Methodology'
2. Population for whom poverty status is determined

Table 1 A. Individuals with ncome to Poverty Ratio of <1.99
Total

Population
District 1
District 2
District 3
District 4
District 5

Total

Individuals with

Percent of Individuals

Income to Poverty

with Income to Poverty

1

1,2

Ratio of <1,99

Ratio of <1,99

329,595
324,122
331,028
337,499
331,288

47,604
106,192
48,200
58,028
36,784

1,653,532

296,808

16,0%
35,8%
16,2%
19,6%
12,4%
100%

Table 1B,

Range: Individuals with
Range: Total
1,2
Population
District 1
District 2
District 3
District 4
District 5

86,322
88,680
77,425
70,543
72,660

89,032
89,854
79,616
74,573
74,404

Income to Poverty Ratio
1

of <1,99

26,028
24,018
24,563
32,841
42,011

27,127
24,624
24,959
34,889
42,731

‘ This is the highest income to poverty ratio reported in Census 2000 data.
^ The average famiiy size in Santa Ciara County is 3.4i.

Table2A. Families with Family Income <$45,000
Percent of Families

Families w/Family
1

District 5

84,984
64,469
78,221
84,697
87,394

Total

399,765

93,116

District 1
District 2
District 3

District 4

w/Family Income
<$45,000

1

Income <$45,000
16,335
25,064
16,226
21,954
13,537

Total Families

17.5%
26.9%
17.4%
23.6%
14.5%
100%

Table 2B.

Range: Families w/Family

Range: Total Families^
District 1
District 2

District 3
District 4
District 5

318,739
319,512
322,642
318,913
324,254

340,074
329,827
342,454
348,588
342,059

1

Income <$45,000
48,735
46,878
105,474
46,781
55,280
36,045

107,421
49,853
59,305
37,842

Table 3A. Families in Poverty with children <5 years old (can include families with older

children) and Fami ies with children <18 years old
Families with

Children <5yrs^ in
1

Families
District 1

District 5

84,984
64,469
78,221
84,697
87,394

Total

399,765

District 2
District 3
District 4

Families with

Percent of Families

Percent of Families
1

Total

Poverty
1,110
2,876
1,101
1,348

with Children <5yrs Children <18yrs
in Poverty
in Poverty
15.6%

661

9.3%

2,547
5,395
2,356
2,702
1,841

7,096

100%

14,841

40.5%
15.5%
19.0%

with Children <18yrs
in Poverty
17.2%
36.4%
15.9%
18.2%
12.4%

100%

Table 3B.

Range: Families w/Children

Range: Total Families^
District 1

82,071

District 2

63,366
76,161
79,673
85,545

District 3
District 4
District 5

87,781
65,915
80,997
87,717
90,304

<5yrs^ in Poverty
1,095
2,854
1,055
1,261

1,127
2,913
1,157
1,380

643

707

Range: Families w/Children

<18yrs^ in Poverty
2,508
5,368
2,256
2,512
1,782

2,595
5,462
2,476
2,792
1,931

Table 4A. Children <5 years old in poverty
Total Children Children <5 years in Percent of Children
<5 years in Poverty
Poverty^
<5 years^
16.4%

1,556
4,029
1,385
1,695

District 5

23,821
25,990
23,865
22,837
19,417

812

8.6%

Total

115,930

9,477

100%

District 1
District 2
District 3
District 4

42.5%

14.6%
17.9%

Table 4B.

Range: Children <5

Range: Total Children

1

1

in Poverty
16,722
16,100
25,463
24,806
16,783
15,817
22,520
20,826
13,963
13,232

<5 years
District 1
District 2

District 3
District 4
District 5

87,781
65,915
80,997
87,717
90,304

82,071
63,366
76,161
79,673
85,545

Table 5A. Children <18 years old in poverty
Percent of
Total Children

<18 years

1

Children <18
1

years In Poverty

District 4

74,573

District 5

74,404

6,237
15,321
5,474
5,848
3,669

407,479

36,549

District 2

89,032
89,854

District 3

79,616

District 1

Total

Children <18 years
in Po\/erty
17.1%

41.9%
15.0%

16.0%
10.0%

100%

I

Table 5B.

Range: Total Children

Range: Children

<18 years^

<18 years in Poverty^

District 3

2,256

2,476

1,055

District 4

2,512
1,782

2,792
1,931

1,261

1,110
2,876
1,101
1,348

643

661

District 1

District 2

District 5

2,508
5,368

2,595
5,462

1,095
2,854

Table 6A. Seniors 65 years and older in Poverty
Total Seniors

Seniors 65yrs+ in

Percent of Seniors

65yrs+^

Poverty^

65yrs+ in Poverty

District 5

27,127
24,624
24,959
34,889
42,731

1,373
2,726
1,552
2,418
1,773

Total

154,330

9,842

District 1
District 2
District 3
District 4

14.0%

27.7%
15.8%
24.6%

18.0%
100%

Table 6B.

Range: Seniors 65yrs+
1

in Poverty^

Range: Total Seniors 65yrs+
District 1
District 2
District 3
District 4
District 5

82,071
63,366
76,161
79,673
85,545

84,984
64,469
78,221
84,697
87,394

2,508
5,368
2,256
2,512
1,782

2,547
5,395
2,356
2,702
1,841