EXPLANATORY NOTES
INTRODUCTION
1 This publication presents preliminary estimates of Australia's international trade in goods and services on a balance of payments basis and merchandise import and export statistics on a recorded trade basis.
2 Merchandise trade statistics on a recorded trade basis are compiled from information submitted by exporters and importers or their agents to the Australian Customs Service (ACS). Adjustments for coverage, timing and valuation are made to recorded trade data to convert them to a balance of payments basis. The main source for services data is the quarterly Survey of International Trade in Services.
3 More comprehensive quarterly estimates of Australia’s trade in goods and services, together with comprehensive details of Australia’s balance of payments are included in the quarterly publication, Balance of Payments and International Investment Position, Australia (cat. no. 5302.0). Detailed monthly statistics on merchandise trade are available on Time Series Spreadsheets or by subscription to tailored services.
CONCEPTS, SOURCES AND METHODS
4 The conceptual framework used in compiling Australia's merchandise trade statistics can be found in International Merchandise Trade, Australia: Concepts, Sources and Methods, 2001 (cat. no. 5489.0).
5 The conceptual framework used in compiling Australia's balance of payments statistics is based on the Fifth Edition of the International Monetary Fund's Balance of Payments Manual (BPM5,1993). Descriptions of the underlying concepts and structure of the balance of payments and the sources, methods and terms used in compiling the estimates are presented in Balance of Payments and International Investment Position, Australia: Concepts, Sources and Methods, 1998 (cat. no. 5331.0). To bring merchandise trade statistics on a recorded trade basis to a balance of payments basis, timing adjustments are made to ensure that the transaction is recorded in the period in which ownership changed, rather than in the period in which the transaction was recorded by ACS. Adjustments are also made to account for the change of ownership of goods not included in merchandise trade statistics. Chapter 6 of cat. no. 5331.0 provides more detail on the relationship between statistics on international merchandise trade on a recorded trade basis and on a balance of payments basis.
6 Both of the Concepts, Sources and Methods publications are available to download for free from the ABS website. Select Methods, Classifications, Concepts & Standards, then choose ABS concepts, classifications and statistical standards and then the catalogue numbers as above.
SEASONAL ADJUSTMENT
7 The estimates of international trade in goods and services on a balance of payments basis are seasonally adjusted, however the merchandise exports and imports statistics on a recorded trade basis are not. Monthly original estimates are volatile, being subject to calendar-related and large irregular influences. Seasonally adjusted estimates are derived by estimating and removing from the original series systematic calendar related effects, such as seasonal, trading day, length of month and moving holiday influences. Seasonal adjustment does not aim to remove the irregular or non-seasonal influences which may be present in any particular month. These irregular influences may reflect both random economic events and difficulties of statistical recording.
8 The seasonally adjusted statistics in this publication use the concurrent seasonal adjustment technique and Autoregressive Integrated Moving Average (ARIMA) Modelling to estimate factors for the current and previous months. Under concurrent seasonal adjustment, the estimates of seasonal factors are fine tuned as new original estimates become available each period. The seasonally adjusted estimates are subject to revisions at each reference month as the estimates of seasonal factors are improved. For more information on seasonal adjustment methods, see Information Paper: An Introductory Course on Time Series Analysis, Jan 2005 (cat. no. 1346.0.55.001), Time Series Analysis Frequently Asked Questions, 2003 (cat. no. 1346.0.55.002), alternatively contact the Assistant Director, Time Series Analysis on (02) 6252 6345 or e-mail <time.series.analysis@abs.gov.au>.
ARIMA MODELLING
9 ARIMA modelling relies on the characteristics of the series being analysed to project future period data. ARIMA modelling is used on a case-by-case basis where it results in reduced revisions to seasonally adjusted series when subsequent data become available. The projected values are temporary, intermediate values, that are only used internally to improve the estimation of the seasonal factors. The projected data do not affect the original estimates and are discarded at the end of the seasonal adjustment process. The ARIMA model is assessed as part of the annual reanalysis and, following the 2008 annual re-analysis, 41 of the 42 directly seasonally adjusted trade in goods and services time series use an ARIMA model. For more information on the details of ARIMA modelling see Feature article: Use of ARIMA modelling to reduce revisions in the October 2004 issue of Australian Economic Indicators (cat. no. 1350.0).
TREND ESTIMATES
10 The month-to-month movements of the seasonally adjusted estimates may not be reliable indicators of trend behaviour because they include irregular or non-seasonal movements. Trend estimates are derived by applying a 13-term Henderson moving average to the seasonally adjusted series. The use of a 13-term Henderson average can result in revisions to the estimates for the most recent six months as additional observations become available. Revisions can also occur because of changes in the original data and as a result of the re-estimation of the seasonal factors. For more information on trend estimates methods, see Information Paper: A Guide to Interpreting Time Series - Monitoring Trends (cat. no. 1349.0), alternatively contact the Assistant Director, Time Series Analysis on (02) 6252 6345 or e-mail <time.series.analysis@abs.gov.au>.
SIGN CONVENTION
11 In keeping with balance of payments conventions, where statistics are on a balance of payments basis, credit entries (exports) are shown without sign and debit items (imports) are shown as negative entries. For statistics on a recorded trade basis, both imports and exports are shown without sign. The calculation of percentage changes on balance of payments debit items are made without regard to sign. References to balance of payments debit items in Key Figures, Key Points, and Analysis and Comments are also made without regard to sign.
COMMODITY BREAKDOWNS OF GOODS
12 For details of the classifications used to present goods exports (credits) and imports (debits) on a balance of payments basis, see tables 6.6 and 6.7, respectively, in Balance of Payments and International Investment Position, Australia: Concepts, Sources and Methods, 1998 (cat. no. 5331.0).
13 The correspondences used to compile statistics on a Balance of Payments basis were updated in the July 2008 issue with estimates for all time periods recompiled on the basis of the revised correspondences to maintain consistency in the time series.
14 The recorded trade statistics shown in tables 12 and 13 are classified by the Standard International Trade Classification (SITC). Imports and exports of goods at a more detailed level are available from the Time Series spreadsheets. All data from July 2005 are presented according to SITC Rev 4 and data prior to July 2005 are presented according to SITC Rev 3. For details refer to the July 2008 issue of this publication.
COMMODITY BREAKDOWNS OF SERVICES
15 The quarterly detailed services data published in table 11 are consistent with the monthly aggregates shown in table 9.
16 Monthly indicators for many of the services components that are only surveyed quarterly are not available. In particular, the Freight and Other transportation components of Total services credits are not available for publication on a monthly basis. The estimates for these items shown in table 9 are therefore derived by dividing the quarterly estimate by three. Where quarterly survey data are not available, freight debits are derived directly from imports data for the reference month as a difference between total merchandise cost, insurance and freight (CIF) and free on board (FOB), adjusted to reflect timing and processing adjustments. For freight credits and other transportation credits and debits, estimates are derived by extrapolating the last month's data by an average of movements for the same month over the three previous years.
CONFIDENTIALITY OF MERCHANDISE TRADE STATISTICS
17 The release of statistics for certain merchandise trade commodities is restricted in order to prevent the identification of the activities of an individual business, where this is requested by the business concerned. These restrictions do not affect the total value of exports and imports, but they can affect statistics at the country, state and commodity levels. Imports data that have the confidentiality restrictions 'No commodity details' or 'No value details' are aggregated into a single confidential commodity code. For data prior to September 2008, these data are added back into the appropriate state total and country total (i.e. these totals show the correct level of trade). From September 2008 these confidential data are not added back. Instead the confidential data are published as 'No country details' in the country totals and 'State not available for publication' in the state totals. Therefore, country and state totals from September 2008 may not represent the actual amount of trade in each country/state but only the trade in commodities without a 'No commodity details' or 'No value details' restriction. For information on the confidentiality restrictions applied to the merchandise trade statistics in this publication, refer to the current International merchandise trade: Confidential Commodities List (CCL) (cat. no. 5372.0.55.001) which can be accessed from ABS web site.
TOURISM RELATED SERVICES
18 The tourism related services memorandum items provide timely indicators of the movements in tourism related activities, not an absolute measure of the level of these activities. These series are not compiled on a balance of payments conceptual basis. However, they do provide a reasonable approximation of world tourism related activities.
19 The memorandum items have been derived by re-aggregating relevant components of the international trade in services series of the balance of payments accounts. The tourism related indicator has been derived by combining total travel services (business, education-related and other personal travel) and passenger transportation services (which includes agency fees and commission receipts for air transport).
SERVICES BY STATE AND BY PARTNER COUNTRY
20 Annual services data by state and by partner country are released twice yearly. Calendar year data are usually released with the March issue of this publication and financial year data are released with the September issue. Refer to Time series data for details.
21 Services credits are classified by the state of provision, while services debits are classified by the state of consumption. The state allocations for transportation, travel and communication services are based on a number of indicators including merchandise trade statistics by state, overseas passenger arrivals and departures by state of clearance and data provided by the Department of Education, Science and Training. The allocation for other services (about 25% of all trade in services) is primarily based on the location of the business reporting the information, which serves as a proxy for the state of provision/consumption of that service. The data should be used with care but are considered suitable for analysis over time.
22 A comprehensive explanation of the data sources used and the methodology applied in the compilation of partner country statistics is provided in Chapter 17 of Balance of Payments and International Investment Position, Australia - Concepts, Sources and Methods (cat. no. 5331.0). Approximately 7% of total services credits and 5% of total services debits for both 2006-07 and 2007-08 are either confidential, or unable to be allocated to individual countries.
ABS DATA AVAILABLE
23 More detailed balance of payments and recorded merchandise trade data, including forward seasonal factors are available as time series spreadsheets or data cubes from the ABS website.
24 More detailed merchandise trade data by commodity, country and state, and statistics included in this and related publications are available on request. Inquiries should be made to the National Information and Referral Service as shown on the back of this publication.
RELATED PRODUCTS AND PUBLICATIONS
25 Users may also wish to refer to the following publications which can be downloaded free of charge from the ABS web site:
26 Current publications and other products released by the ABS are available from the
Statistics View. The ABS also issues a daily
Release Advice on the web site which details products to be released in the week ahead.
CAUTIONARY NOTE
27 The tables in this publication are presented on two bases. Tables 1-11 contain estimates of Australia's international trade in goods and services which have been adjusted for coverage, valuation and timing to a balance of payments basis. Tables 12-15 contain estimates of merchandise exports and imports based on Australian Customs Service records. Paragraph 5 of the Explanatory Notes provides an explanation of the difference between these bases.
ROUNDING
28 Where figures have been rounded, discrepancies may occur between sums of the component items and totals. Percentage movements are calculated from data at the level of precision presented in this publication (i.e. $m) except for international merchandise trade tables.