EXPLANATORY NOTES


INTRODUCTION

1 This publication presents estimates from various Australian Bureau of Statistics (ABS) wheat surveys and from administrative data relating to wheat exports. This information informs policy and decision making following the passage of the Wheat Export Marketing Bill on 1 July 2008.


SCOPE AND COVERAGE

2 Estimates in this publication are based on information obtained from the following ABS surveys:

• Grain (Wheat) Handlers Stocks Survey (GHSS) - Monthly
• Wheat Export Sales Survey (WESS) - Monthly

3 The data on wheat grain exported are compiled by the ABS from information submitted by exporters or their agents to the Australian Customs Service. These data may be subject to revision.

4 The coverage of the Grain (Wheat) Handlers Stocks Survey (GHSS) is all major bulk grain handlers. The GHSS was previously conducted on a quarterly basis, but from March 2009 the GHSS has been conducted and data published on a monthly basis.

5 The coverage of the Wheat Export Sales Survey (WESS) includes businesses reporting wheat grain exports on documentation lodged with the Australian Customs Service and units on the Department of Agriculture, Fisheries and Forestry (DAFF) Wheat Export Charge (WEC) levy register.


RELIABILITY OF ESTIMATES

6 Major grain handlers and approximately 50 major wheat exporters are surveyed through the Grain (Wheat) Handlers Stocks Survey (GHSS) and Wheat Export Sales Survey (WESS).

7 A minimum response rate of at least 90% is generally achieved for the monthly wheat collections.

8 Some of the estimates in this publication are based on information obtained from samples drawn from the total business population in scope of these collections. As such, estimates are subject to sampling variability; that is, they may differ from the figures that would have been produced if all businesses had been included in the surveys. One measure of the likely difference is given by the standard error (SE) which indicates the extent to which an estimate might vary by chance because only a sample was taken. There are about two chances in three that a 'sample' estimate will differ by less than one SE from the figure that would have been obtained if all businesses had responded, and about nineteen chances in twenty that the difference will be less than two SEs.

9 In this publication, 'sampling' variability of the estimates is measured by the relative standard error (RSE) which is obtained by expressing the SE as a percentage of the estimate to which it refers.

10 RSEs of 10% or greater are published as data cell comments in the datacubes available for download with the Wheat Stocks and Exports, Australia (cat. no 7307.0) publication. Most published national estimates have RSEs of less than 10%. However some state estimates have RSEs greater than 10%. Estimates that have an estimated RSE between 10% and 25% should be used with caution as they are subject to sampling variability too high for some purposes. Estimates with an RSE between 25% and 50% should be used with caution as it is subject to sampling variability too high for most practical purposes. Estimates with an RSE greater than 50% are considered too unreliable for general use. Separate indication of the RSEs of all estimates is available on request.


ROUNDING

11 Where figures have been rounded, discrepancies may occur between sums of the component items and totals.


ABS DATA AVAILABLE ON REQUEST

12 Not all data from these surveys are published here. As well as the statistics included in this and related publications, the ABS may have other relevant data available on request. Inquiries should be made to the National Information and Referral Service on 1300 135 070.


GENERAL ACKNOWLEDGMENT

13 ABS publications draw extensively on information provided freely by individuals, businesses, governments and other organisations. Their continued cooperation is very much appreciated. Without it, the wide range of statistics published by the ABS would not be available. Information received by the ABS is treated in strict confidence as required by the Census and Statistics Act 1905.


RELATED PUBLICATIONS

14 A range of other publications relevant to the Agriculture sector is produced by the ABS, including:

• Agricultural Commodities, Australia (cat. no. 7121.0)
• Principal Agricultural Commodities, Australia, Preliminary (cat. no. 7111.0)
• Value of Agricultural Commodities Produced Australia (cat. no. 7503.0)
• Livestock and Meat, Australia (cat. no. 7218.0.55.001)
• Livestock Products, Australia (cat. no. 7215.0)
• Water Use on Australian Farms (cat. no. 4618.0)

15 Detailed merchandise exports data are available by contacting the National Information and Referral Service on 1300 135 070. Value and quantity data can be produced according to a number of commodity classifications, with information available by state/territory of origin, and country of destination.

16 Current publications and other products released by the ABS are listed under the Topics @ a Glance pages on the ABS website <https://www.abs.gov.au>. The ABS also issues a daily Release Advice on the website which details products to be released in the week ahead.