Survey of Grain Used for Industrial Purposes

Detailed information for March 31, 2011

This is a survey of plants using grain mainly to produce ethanol or biodiesel in western Canada.

Data release - the data are only released internally to Statistics Canada for other surveys to use as part of their data sources

• Description
• Data sources and methodology
• Data accuracy

Description

This is a survey of plants using grain mainly to produce ethanol or biodiesel in western Canada. There are few plants, but their numbers are increasing and they use significant volumes of grain. The use data are split into purchases from licensed grain companies and from farmers.

The data are required by the Agriculture Division of Statistics Canada for calculations of grain deliveries and supply-demand.

Collection period: The survey is conducted three times per year to coincide with calculations of farm stocks at December 31, March 31 and July 31.

Subjects

• Agriculture and food (formerly Agriculture)
• Crops and horticulture

Data sources and methodology

Target population

The target population consists of plants using grain mainly to produce ethanol or biodiesel in Western Canada. Plants using grain for other industrial purposes may also be surveyed.

This is a census of all known companies in Western Canada that use grain for industrial purposes. The total sample size for this survey is approximately 8 units.

Instrument design

The questionnaire was designed in consultation with internal and external specialists, as well as some respondents, before the start of the survey in 2008.

Sampling

This survey is a census with a cross-sectional design.

Data are collected for all units of the target population, therefore, no sampling is done.

Data sources

Responding to this survey is mandatory.

Data are collected directly from survey respondents.

The first collection period was in July 2008. The collection is done by mail with mail/facsimile and telephone follow-up.

The questionnaire asks for the crop year to-date quantities of grain used, primarily wheat and corn, and on the stocks of grain at the plants.

Error detection

Data are compared to the previous reports to ensure the data are at least equal to the crop year to-date data reported earlier.

Reported data are also compared to previous reports to ensure that the commodities reported are the same.

Any changes are reviewed for reasonableness given grain pricing and plant capacity.

Imputation

Since this is a new survey, data are not generally imputed.

Estimation

This methodology type does not apply to this statistical program.

Quality evaluation

This is a census and the data quality is maintained by standard editing techniques which are rigorous. Apparent data discrepancies are either scrutinized by professional staff or the company involved is contacted. Supply and disposition trends, used by government and industry stakeholders, help to confirm the results of the survey.

Disclosure control

Statistics Canada is prohibited by law from releasing any information it collects which could identify any person, business, or organization, unless consent has been given by the respondent or as permitted by the Statistics Act. Various confidentiality rules are applied to all data that are released or published to prevent the publication or disclosure of any information deemed confidential. If necessary, data are suppressed to prevent direct or residual disclosure of identifiable data.

Revisions and seasonal adjustment

Data are revised for non-response or for incorrect reporting when revisions are received. The survey data are not benchmarked.

Data accuracy

Since this is not a sample survey, there is no sampling error.

While considerable effort is made to ensure high standards throughout all stages of collection and processing, the resulting estimates are inevitably subject to a certain degree of non-sampling error. Examples of non-sampling error are coverage error, data response error, non-response error and processing error. The major source of non-sampling error for this survey is considered to be coverage error and non-response error.

Coverage error can result from incomplete listing and inadequate coverage of the population of biofuel plants.

Data response error may be due to questionnaire design, the characteristics of a question, inability or unwillingness of the respondent to provide correct information, misinterpretation of the questions or definitional problems. These errors are controlled through careful questionnaire design and the use of simple concepts and consistency checks. However, this survey is relatively new and some respondents may not be well versed in the survey concepts which introduces some non-sampling error.

Non-response error is related to respondents that may refuse to answer, are unable to respond or are too late in reporting. In these cases, data are generally not imputed. Attempts are therefore made to obtain as high a response rate as possible. Final response for this survey is expected to be 90%.

Processing error may occur at various stages of processing such as data entry, editing and tabulation. Measures have been taken to minimize these errors. A few trained staff work on this survey and review the estimates. Tabulation is automated to eliminate human error.