Download - Recent Improvements for Dual-Frame RDD Sampling Methodology 29 th Annual Meeting March 26, 2012
Recent Improvementsfor
Dual-Frame RDD Sampling Methodology
29th Annual MeetingMarch 26, 2012
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Presentation Outline
Dual-Frame RDD: Sampling considerations
Weighting considerations
Areas of Improvement: The moving target for cellphone-only (CPO) households
The evolving landline frame
Solution: Better quantification of CPO households
New landline frame to cover virtually all landline households
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Sampling Considerations
A representative sample mirrors its target population:
Geographic characteristics: state and counties
Demographic characteristics: gender, race, age, education, etc.
Behavioral characteristics: telephone status (CPO)
BRFSS sampling design is non-EPSEM:
Disproportionate stratified sampling (CSS) for landlines
Provisional mixture of cellular and landline households
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Weighting Considerations
Weights are needed to compensate for: Differential selection probabilities (by design) Design
Weights
Differential nonresponse rates Poststratified/Raked Weights ACS/CPS estimates for geodemographic target totals CDC estimates for CPO households
Cost of weighting:
2
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2
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wnn
wcvUWEB
ias
Standard Deviation
MSE = Variance + Bias2
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Areas of Improvement
Growing/changing CPO households can lead to:
Sampling inefficiencies (particularly in small areas)
Weighting inconsistencies
Landline frame may leave out certain assignments:
Less systematic assignment of new numbers
New providers assign numbers outside of the frame
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Areas of Improvement(CPO Household)
Research community indebted to the CDC for CPO estimates:
Survey based
Available at the state level and certain smaller areas
Current CPO estimates are critical:
Efficient sample mixture
Effective weighting strategy
Eliminating the need for screening out dual-users
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Areas of Improvement(CPO Households)
ALARAZCACOCTDCDEFLGAIAIDILINKSKYLAMAMDMEMIMNMOMSMTNCNDNENHNJNMNVNYOHOKORPAPWSCSDTNTXUTVAVTWAWIWVWY
CDC-07 CDC-10
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Areas of Improvement(Landline Frame)
Available Landlines 100-Series Banks (NPA-NXX-XX00 – NPA-NXX-XX99)
2.9M
1.9M
4.3M
0.7M
Potential Undercoverage of 1+Listed Frame
Brick et al. (POQ, Vol. 59, 1995): Less than 4%Fahimi et al. (POQ, Vol. 73, 2009): About 20% Boyle et al. (POQ, Vol. 73, 2009): About 5% Barron et al. (SP, April 2010): Between 7 to 14%Weiss et al. (AAPOR 2011): 0-Listed can be more
productive
1+Listed 0-Listed
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Areas of Improvement(Declining Listed Numbers)
2005 2007 2009 2010-10 2011-01 2011-04 2011-10
76,923,90374,518,722
72,578,043
67,739,38465,751,221 64,781,241
62,396,939
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Solution(New Landline RDD Frame)
Traditional frame includes only 1+listed banks
Need a new frame that includes 1+assigned banks
Each bank will be indexed by its number of: Listed assignments
Unlisted assignments
Can accommodate various sampling options: K-Assigned RDD sampling, K 1
True PPS with MOS = f (assignment density of banks)
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Solution(Counts of CPO Households at the County
Level)
Obtain counts of telephone households (landline or cellular) for each county
Obtain counts of landline households in each county
Triangulate counts of CPO households for each of the 3,141 counties by:
Telephone Households - Landline Households
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Solution (Distribution of Multi-line Households from
BRFSS)
AK AR CA CT DEGA HI ID IN KY
MA MEMN MS NC NE NJ
NV OH OR PR SC TN UT VIW
AW
V0.0%
1.5%
3.0%
4.5%
Urban SuburbanRural
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Solution(Distribution of Landline Households by
County)
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Solution(Counts of CPO Households at the County
Level)
1 31410%
20%
40%
60%
80%
100%
US Counties (1 to 3141)
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Solution(Clark County Idaho is Mostly CPO)
Most 294 households serviced by Mud Lake Telephone Cooperative Association (MLTCA)
MLTCA provides Canopy Wireless Internet Service (CWIS) to residences and businesses
CWIS is a cost-effective alternative for broadband in areas where it is cost-prohibitive to upgrade the old wireline infrastructure
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Solution(More Efficient Sampling/Weighting Practices)
WY
WV WI
VT
VAVATXTXTXTXTNTNSD SCPAOKOKOHNY
NM NENE
NDNC
MT
MS
MO
MO
MN MI
MI
MALAKYKYKS IN IN IL ID IA IA GAGA FL
COCAAZ
ARAL
0%
50%
100%(CPO Households by County and State)
County-CPO State-CPO
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Solution(More Efficient Sampling/Weighting Practices)
CT
NH
VT
DE
MA
LA
PA IA PA
AL IN WI
NJ
KS
MN
WV
MD
OK
SD MI
KY
AK
NC
ME
GA IL TN
MO
VA
CA
CO
OH
WA FL
NE
MT
SC
NY
ND
MS
AR
UT
OR
NV HI
TX
AZ
NM ID DC
WY
0%
10%
20%
30%
40%
50%
CDC-07 CDC-10 MSG-12
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Conclusions
Dual-frame RDD provides an effective alternative for probability-based sampling for scientific surveys: Proper mixture of landline and cellular numbers
Efficient weighting using current CPO estimates
Quarterly estimates of CPO households at the county level will help states: Higher quality survey estimates
Eliminate the need for expensive screening of dual users
A more comprehensive landline frame covers landline households with numbers outside of the 1+listed frame
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Contact