Designing the 2007 Commodity Flow Survey Authors: Scot Dahl, William C. Davie, Jr US Census Bureau Presented by: Ruth Detlefsen US Census Bureau June 19,

Designing the 2007 Commodity Flow Survey

Authors: Scot Dahl, William C. Davie, Jr US Census Bureau

Presented by: Ruth Detlefsen

US Census Bureau

June 19, 2007

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Survey Description

• Conducted once every five years

• Partnership with BTS

• Includes establishments in mining, manufacturing, wholesale, and some retail and services industries

• Also selected auxiliary establishments

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Summary of Changes for 2007

• Scope & Coverage

• Frame Data

• Questionnaire design

• Sample design

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Scope & Coverage Considerations

• Added retail fuel oil dealers – NAICS 45431

• Added publishers – NAICS 5111 & 51223

• Conduct an advance survey of auxiliaries

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Frame Improvement• Improved quality of data associated

with auxiliaries

• Frame counts Table 1: 2007 CFS FrameTrade Area Counts

Mining 6,789 Manufactuing 327,826 Wholesale 356,477 Retail 25,190 Services 22,539 Auxiliaries 14,878 Total 753,699

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Auxiliaries

• Support establishments of multi-unit companies

• CFS includes auxiliaries in:– Warehousing & storage (NAICS 4931)– Corporate, Subsidiary, & Regional

Managing Offices (NAICS 551114)

• Many are not shippers• Initial estimate of shipping activity is

deficient for those that ship

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Advance Survey

In 2006, conducted an advance survey:• One page questionnaire, 2 versions

– Auxiliaries (NAICS 4931 & 551114)– Other large inscope establishments

• Purpose:– Identify non-shipping auxiliaries– Improve measure of shipping activity for

auxiliaries (annual value of shipments)– Identify a contact person for all

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Advance Survey

Response rates:

• Auxiliaries: 87%

• Large establishments: 75%

Table 2: Shipper Status of Advance Survey ResponsesShipper Status Aux Large Total

Shipper 10,716 32,275 42,991Non-Shipper 24,220 1,561 25,781Non-respondents 5,061 11,139 16,200

Total 39,997 44,975 84,972

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Advance Survey

Measures of shipment activity

Not reported 1,130 Less than 5 4,451 5 - 20 1,652 20 - 50 1,020 50 - 200 1,225 200 - 500 566 500 - 1,000 322 1,000 - 5,000 304 5,000 or more 46

Total 10,716

Table 3: Shipping AuxiliariesNumber of auxiliaries

Annual value of Shipments ($mil)

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Questionnaire Development

• Three rounds of cognitive visits• Questionnaire changes

– Improved layout and question flow– Greater standardization throughout form – Improved sampling instructions– More consistency between form, instructions, and

the commodity manual– “Intermodal” checkbox– 3PL questions on 4th quarter form

• Electronic spreadsheet response option

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Issues - 3PLs

• Many companies outsource part or all of their logistics operations

• These Third Party Logistics (3PL) providers are not in-scope to the CFS

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3PLs - Example

From an SEC filing:

• Company A sells its warehouse to Company B, a real estate investment company

• Company B in turn leases the warehouse to Company C

• Company C will provide warehousing and distribution services for Company A

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Sample Design

Features:

• Three stages of sampling

• Sample size of ~100,000 establishments

• Primary strata based on geography and industry

• Additional stratification based on size

• Special HAZMAT strata

• Special auxiliary strata

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Geographic Strata

• 123 primary geographic strata– 73 metropolitan area strata– 50 balance of state strata

• Some metropolitan areas are split by state boundaries

• For 2007, ten metropolitan areas were added.

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Geographic StrataTable 4: Metropolitan Area Additions for 2007 CFSCSA CBSA CSA / CBSA Description132 Baton Rouge-Pierre Part, LA CSA

13140 Beaumont-Port Arthur, TX MSA

16700 Charleston-North Charleston, SC MSA

204 Corpus Christi-Kingsville, TX CSA

21340 El Paso, TX MSA

278 Hartford-West Hartford-Willimantic, CT CSA

324 Lake Charles-Jennings, LA CSA

29700 Laredo, TX MSA

380 Mobile-Daphne-Fairhope, AL CSA

496 Savannah-Hinesville-Fort Stewart, GA CSA

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Industry Strata

• Up to 45 industry strata within each geographic area

– Mining (3 industries)– Manufacturing (21 industries)– Wholesale (18 industries)– Non-store Retail (1 industry)– Retail fuel oil dealers (1 industry)– Publishers (1 industry)

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Special HAZMAT Strata

• Used 2002 CFS data to identify 6-digit NAICS industries associated with six groups of HAZMAT shipments.

– Ammonium nitrate– Ethanol– Explosives– Hydrogen– Toxic by inhalation– All other hazardous materials

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Special HAZMAT Strata

325311 Take all n/a424690 Sample State

424910 Sample State

311221 Take all n/a325193 Take all n/a424210 Sample State325920 Take all n/a332992 Take all n/a336414 Take all n/a336415 Take all n/a325998 Sample National325120 Sample325188 Sample325199 Sample

Toxic by Inhalation 325181 Take all n/a324110 Take all n/a424710 Sample State

HAZMAT Group Sample?

Table 5: HAZMAT Strata

Other HAZMAT

NAICS

National

Ammonium Nitrate

Ethanol

Explosives

Hydrogen

Geo Strata?

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Auxiliary Strata

• For auxiliaries that responded to the Advance survey (shippers only):

– 123 strata (one for each geographic stratum)

– Combined NAICS 4931 and 551114

• For non-responding auxiliaries:– 1 national stratum for 4931 (warehouses)– 1 national stratum for 551115

(management offices)

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Summary of Stratification

• Sample stratification summary

Overall Primary Strata NumberDo not collapse 1,306Collapsed 1,154Auxiliaries (Advance Survey responders) 123Auxiliaries (Advance Survey non-responders) 2HAZMAT 160

Total Primary Strata 2,745

Table 6: Summary of Primary Stratification

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Design Constraints

• Sample size of about 100,000 establishments

• CV of about 1.5% for each primary stratum

• Maximum first-stage (establishment) weight of 100

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Sample Sizes

• Considered three designs:– Primary stratum CV = 1.5%,

No national industry level CV constraintNote: Achieved national CV of 0.057%

– Primary stratum CV = 1.6%, National industry level CV = 0.04%

– Primary stratum CV = 1.7%, National industry level CV = 0.036%

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Sample Sizes

• Summary of Sample Designs

P/S CV=1.5%(Natl CV=0.057%)

Count Count Count % chg Count % chg

Auxiliary 14,878 2,981 4,376 46.8 4,713 58.1

Manufacturing 327,826 44,835 45,367 1.2 45,285 1.0

Mining 6,789 3,003 2,926 (2.6) 2,846 (5.2)

Other 22,539 2,035 2,051 0.8 2,033 (0.1)

Retail 25,190 2,784 2,688 (3.4) 2,562 (8.0)

Wholesale 356,477 44,629 44,740 0.2 44,930 0.7

TOTAL 753,699 100,267 102,148 1.9 102,369 2.1

Total Sample SizeP/S CV=1.6%

Natl CV=0.04%Trade Area

UniverseP/S CV=1.7%

Natl CV=0.036%

Table 8A: Total Sample Size of Alternative CFS Designs

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Summary

• Recap of 2007 CFS changes:– Expanded industry coverage– Use of Advance survey to improve quality

of frame data for auxiliaries– A redesigned questionnaire– Larger sample size– More detailed geography and industry

stratification– National CV constraint on sample design

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Thank you!

Contacts:

• [email protected]

• [email protected]