Collecting Electronic Data From the Carriers:
the Key to Success in the
Canadian Trucking Commodity Origin and Destination Survey
François Gagnon and Krista Cook
Statistics Canada
ICES III, Montreal, June 2007
PRESENTATION
Outline
1. Background
2. Methodology of the Redesigned Survey
3. Advantages/Disadvantages of the
Canadian Approach
4. Challenges of Collecting Electronic Data
5. Conclusion
1. BACKGROUND
Commodity Flow Surveys in Canada
Shipments
Ship
from admin
data (census)
Rail
from admin
data (census)
Truck
TCOD
1. BACKGROUND
What is TCOD?
– Purpose : To measure trucking commodity movements
– Unit of interest : Shipments
– Variables collected for each shipment :
• commodity carried, tonnage
• origin and destination of shipment
• distance, transportation revenues
– Outputs : Estimates and CVs, microdata file
– Input to :
System of National Accounts
– Main user & Co-sponsor:
Transport Canada
1. BACKGROUND
Why a redesign?
- TCOD was developed in the early 1970s
- In 2000, Statistics Canada approved a multiyear project to redesign the survey
 To improve data quality
 To better meet the new requirements of the
users
- Constraint: no additional production costs
1. BACKGROUND
Addressing data coverage needs
Needs identified and decisions made
 Trucking industry
 Long-distance & local
  $1M (in terms of company revenue)
 < $1M (in terms of company revenue)
 Trucking activity in non-trucking businesses
(Private trucking)
 Foreign companies : no frame for now
1. BACKGROUND
Addressing other needs




Annual data
Provincial & Territorial estimates
Improve precision
Other variables such as “value of shipment”:
not available on shipping documents
=> Improve coverage + precision + detail AT
NO ADDITIONAL COST: a good challenge!
2. REDESIGNED TCOD
Coverage of the Old and New TCODs
(Number of Companies)
Trucking companies
Non-trucking companies
Revenue
1,828 351
1,462
$1M
Long Distance Hhld goods
moving
Local
Other trucking
activity
Canadian Companies
Old TCOD Coverage
Added Coverage in the new TCOD
Foreign
Companies
Source: BR - 2004
2. REDESIGNED TCOD
Key estimates to be produced
Key domains: Matrix: Origin x Destination x Commodity
NFLD
051:
061:
NFLD …
…
991:
051:
061:
P.E.I. …
…
991:
051:
… 061:
…
…
991:
051:
061:
B.C. …
…
991:
…
P.E.I.
051:
061:
…
…
991:
051:
061:
…
…
991:
051:
061:
…
…
991:
051:
061:
…
…
991:
051:
061:
…
…
991:
051:
061:
…
…
991:
051:
061:
…
…
991:
051:
061:
…
…
991:
B.C.
051:
061:
…
…
991:
051:
061:
…
…
991:
051:
061:
…
…
991:
051:
061:
…
…
991:
=> Sample size in each cell
of the matrix is random
Key variables of interest: => Tonnage, Distance, Revenue
2. REDESIGNED TCOD
Need for a larger sample size
Main challenge of commodity flow surveys:
No efficient stratification possible to control
sample size by estimation domain
(O/D/Commodity cells)
=> random sample size in O/D/Commodity cells
=> poor precision in many estimation domains
One solution: increase sample size
 Old TCOD: 0.5 M shipments (sampling fraction: 0.8%)
 New TCOD: 7.4 M shipments (sampling fraction: 11.2%)
2. REDESIGNED TCOD
Data Collection
A) Personal on-site visits
Similar process to the old TCOD
Improved CAPI application
79% of the sampled companies (was 91%)
 reduction of the overall collection costs
(since this collection method is expensive)
• 0.2 M shipments (comparable to the old TCOD)
2. REDESIGNED TCOD
Data Collection
B) Profiling using CATI
Used for all companies with < 50 combinations of
Origin/Destination/Type of commodity
21% of the sampled companies (was 9%)
3.7 M shipments in the sample (49% of the sample)
=> Profiling allows to:
Reduce collection costs
Improve precision (through an increased sample size)
2. REDESIGNED TCOD
Data Collection
C) Electronic
Data Reporting (EDR)
► 1st years of the new TCOD
- for the same 7 large companies
- 100% of their data (only 5% in the old TCOD)
- 3.6 M shipments (48% of the total sample)
- automation of coding + imputation
► Future years:
- potentially 200+ companies
=> EDR will allow to:
Reduce collection costs
Improve precision (through an increased sample size)
2. REDESIGNED TCOD
Sample Design
4-Stage Design:
 1st stage: Stratified SRSWOR of companies
 Must-take strata for Profile & EDR companies
> 2nd stage: Sample of a period of time
(e.g., a 6-month period)
> 3rd stage: Systematic sample of shipping documents
> 4th stage: Systematic sample of shipments
2. REDESIGNED TCOD
Domain Estimation
H
Yˆ (d )  
nh
w
1hi
rhit
mhitj
w2 hit  w3hitj  w4 hitjk yhitjk (d )
h 1 i 1
j 1
k 1
where:
yhitjk = value of the variable of interest for the shipment k on
shipping document j from the survey period t of company i in
stratum h
d = domain of interest
 yhitjk if hitjk  d
yhitjk (d )  
0 elsewhere
>> Variance estimation: Jackknife method
3. CANADIAN APPROACH
vs. Other Commodity Flow Surveys
Most other commodity flow surveys
Collect shipment information from the
shippers
Canadian TCOD
Collects shipment information from the
carriers
3. CANADIAN APPROACH
Advantages
Survey population clearly defined:
no subjective decision on which industries (NAICS) to
include
Collection via EDR & profiles
large increase of sample size at a minimal cost
reduces sampling errors
estimates at a more detailed level
On-site collection
reduces non-sampling errors
higher response rate => reduces nonresponse bias
3. CANADIAN APPROACH
Disadvantages
Incomplete coverage of trucking activity
On-site collection is very expensive
Variable “value of commodity” cannot be collected
4. COLLECTING ELECTRONIC DATA
Challenges
Companies’ data vs. TCOD variables
file formats + concepts
Security of electronic data
Automation of the processing
coding of commodities and origin/destination
imputation of commodities
5. CONCLUSION
Canadian Approach
Collection from the carriers:
Larger sampling fraction
=> reduces sampling errors
On-site collection:
=> reduces non-sampling errors
=> higher response rate
Electronic data collection: huge potential to
be developed in future years!
For more
information
please contact
Pour plus
d’information,
veuillez contacter
François Gagnon
Francois.Gagnon@statcan.ca
Krista Cook
Krista.Cook@statcan.ca
www.statcan.ca