Annual Greenhouse, Sod and Nursery Survey (GSNA)

Detailed information for 2016

Status:

Active

Frequency:

Annual

Record number:

3416

The purpose of the survey is to collect information on the production and value of greenhouse products, nursery stocks and sod produced in Canada.

Data release - Scheduled for April 27, 2017

Description

This survey collects data on greenhouse, sod and nursery operations in Canada. The data are used by federal and provincial agriculture departments and producer associations to perform market trend analysis and to study domestic production with particular interest on imports. This survey also contributes to the agricultural receipts program of Statistics Canada and ultimately the System of National Accounts.

The data are used by Agriculture and Agri-Food Canada and other federal departments to develop and administer agricultural policies. This information is also used by provincial departments for production and price analysis and for economic research.

Statistical activity

The survey is administered as part of the Integrated Business Statistics Program (IBSP). The IBSP program has been designed to integrate approximately 200 separate business surveys into a single master survey program. The IBSP aims at collecting industry and product detail at the provincial level while minimizing overlap between different survey questionnaires. The redesigned business survey questionnaires have a consistent look, structure and content. The integrated approach makes reporting easier for firms operating in different industries because they can provide similar information for each branch operation. This way they avoid having to respond to questionnaires that differ for each industry in terms of format, wording and even concepts. The combined results produce more coherent and accurate statistics on the economy.

Reference period: Calendar year

Subjects

  • Agriculture
  • Crops and horticulture

Data sources and methodology

Target population

The target population is all farms in the 10 provinces of Canada that operate any greenhouse, sod, or nursery operations, except for institutional farms and community farms. Farms in the survey frame have been extracted from the Statistics Canada Business Register using the 2011 Census of Agriculture.

Instrument design

The questionnaires were developed by subject matter experts through consultation with the provinces and industry experts. The Operations and Integration Division and the Crops Section of the Collection, Planning and Research Division, Enterprise Statistics Division of Statistics Canada conduct in-house testing for flow and consistency.

Subject matter experts may change, add or remove questions. This typically happens because of changes in market trends or because of information in debriefing reports from field staff.

New questions were pre-tested in the field in 2008 and 2016. This included testing the cognitive process of respondents in answering questions and other tests to obtain feedback for the design of the questionnaire.

Sampling

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

This is a sample survey of farms with one of greenhouse, nursery or sod products with a cross-sectional design.

The sampling unit is the establishment.

For each province, the farms are classified into one of four categories based on the presence or absence of greenhouse, sod and nursery activities and their primary NAICS value. The categories are Greenhouse - Floriculture, Greenhouse - Other, Sod and Nursery. Farms with multiple commodities are assigned to one category based on the importance of their contribution to each category at the provincial level. The category x province combination is called the sampling cell. The farms within each sampling cell are classified into size groups based on area. The sampling stratum is the (category x size) group within the province.

Small operations that have a total greenhouse area smaller than a provincial threshold for total greenhouse area (either floriculture or other greenhouse depending on how they were categorized), have a sod acreage smaller than a provincial threshold for total sod and have a nursery acreage smaller than a provincial threshold for total nursery are excluded from the sample (Take-None); these thresholds are set so that all farms with an acreage greater than any of the four thresholds represent 95% of greenhouse - floriculture, greenhouse - other, sod and nursery acreage in the province together.

In each sampling cell, a threshold for the respective commodity acreage was defined using the sigma-gap method, based on the importance of that commodity to the sampling cell totals. All operations with acreage above one of the thresholds were selected in the sample (Take-All). A similar method was used to identify Take-All farms based on sales information. For the remaining units, the Geometric method was used to divide the strata into 2 groups based on acreage, the large and medium-sized Take-Some. These groups were then collapsed where necessary to ensure that at least 25 units remained in each stratum. A random sample was selected among the operations in each Take-Some stratum.

A sample consisting of 2683 farms was selected by stratified random sampling. Note that while not strictly a census, this sample includes all farms in the population except those in the Take-None portion.

Data sources

Data collection for this reference period: January 9th, 2017 to February 12th, 2017

Responding to this survey is mandatory.

Data are collected directly from survey respondents.

Data are collected annually using an e-mail invitation to open, complete and submit an electronic questionnaire. If the questionnaire is not completed on-line by the deadline date, the respondent will be contacted for a scheduled telephone interview.

View the Questionnaire(s) and reporting guide(s) .

Error detection

New IBSP tools will be utilized to conduct data editing.

We will employ the following methods:

1) Top 20 contributor analysis (macro/micro)
2) Use of historical data for comparison and possible imputation. (micro/macro)
3) Use of various ratios (e.g. price/area) and provincial averages to impute incorrect or missing data (micro)
4) Industry Research - in consultation with Large Agricultural Operations Section team, internet,
provincial and industry specialists.

Imputation

An automated imputation process based primarily on historical data and donor imputation is used. The strategy also uses various ratios (e.g. price/area) and provincial averages. This imputation strategy is used to impute incorrect or missing data for respondents as well as to impute all missing data for non-respondents.

Estimation

The survey data collected are weighted within each stratum in order to produce estimates representative of the population. A ratio adjustment based on the survey estimates compared to the 2011 Census of Agriculture is applied to the estimates to account for the small non-sampled Take-None units. The estimated variances are a combination of variance due to imputation and sampling variance.

Quality evaluation

Daily edits and analysis of the top contributors and historical comparisons are performed before a final estimate is disseminated. Different sources of information are used to validate provincial estimations. No other surveys are available to compare directly with these survey results.

Disclosure control

Statistics Canada is prohibited by law from releasing any information it collects that 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

This methodology type does not apply to this statistical program.

Data accuracy

The Greenhouse, Sod and Nursery Survey usually obtained a response rate between 80 and 85% of survey respondents.

The overall quality of the estimates depends on the combined effect of sampling and non-sampling errors. Sampling errors arise because estimates are derived from sample data and not the entire population. Non-sampling errors are errors which are not related to sampling and may occur throughout the survey operation for many reasons. For example, non-response is an important source of non-sampling error. Coverage, differences in the interpretation of questions, incorrect information from respondents, mistakes in recording, coding and processing of data are other examples of non-sampling errors.

The estimates published are based on a probability sample of farming operations. The potential error introduced by sampling can be estimated from the sample itself by using a statistical measure called the coefficient of variation (CV). Over repeated surveys, 95 times out of 100, the relative difference between a sample estimate and what would have been obtained from an enumeration of all farming operations would be less than twice the coefficient of variation. The sample estimate plus or minus twice the CV is referred to as the confidence interval. For the Annual Greenhouse, Sod and Nursery Survey, CVs at the Canada level range generally from 2% to 10% for the variables that are more frequently reported (area, investment, expenditures, sales, etc.), which makes them very reliable. Some variables on plant, flower and tree varieties have CVs greater than 25%. The coefficients of variation are available upon request.

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