The primary source for exports and imports general merchandise data is the ABS International Merchandise Trade Statistics (IMTS) which is compiled using administrative by-product information from the Australian Customs and Border Protection Service.

The coverage, timing and valuation of these statistics are adjusted, as required, to place them on a balance of payments basis. These adjustments are made using data from the Survey of International Transport Enterprises (SITE) and other sources including the Reserve Bank of Australia and the Survey of International Trade in Services (SITS).

The following adjustments are made:

• Timing adjustments - to ensure transactions are recorded in the period in which ownership changed, rather than in the period in which the transaction was recorded in IMTS. For example:
  • exports and imports of ships and aircraft adjusted to the date on which the business in Australia sells (exports) or takes delivery (imports) where this differs from the date they crossed the customs frontier.
• Coverage adjustments - goods that do not cross the customs frontier but do change ownership. Examples include:
  • large value items of capital equipment such as aircraft, ships and oil rigs subject to finance lease that change ownership between an Australian resident and non-resident but do not cross the customs frontier;
  • goods included in IMTS that are not in-scope of Balance of Payments goods (e.g. goods exported or imported for processing which do not change ownership);
  • goods not captured in IMTS because they are below the low value threshold specified for customs documentation (full import declarations, postal packages and self-assessed clearances);
  • goods exported directly from off-shore installations without crossing Australia's custom's frontier;
  • goods under merchanting; and
  • goods procured in ports.

The chain volume measures for export commodities are obtained by deflating current price values using export price indexes. The processes of chain volume compilation can be read in detail in the ABS publication, Spotlight on National Accounts Australia:  Measuring Chain Volumes for Exports of Goods & Services, July 2011.

The ASNA uses the price indexes underlying those published in  International Trade Price Indexes, Australia.

The chain volume measures of coverage and timing adjustments, that are made to bring exports as recorded in the IMTS onto the required national accounts/balance of payments basis, are also derived using relevant implicit price deflators from  International Trade Price Indexes, Australia.

All volume measures are derived by deflating current price values using detailed price indexes.

All but two of the components are deflated using price indexes derived from those underlying the price indexes published in  International Trade Price Indexes, Australia.

The exceptions are:

• computer equipment - the above-mentioned computer equipment price index from the U.S. Bureau of Economic Analysis; and
• sea transport equipment – a Japanese overseas price index for sea transport equipment adjusted for exchange rate changes.

The principal sources of information on the exports and imports of transportation services are the ABS' International Merchandise Trade Statistics; Survey of International Trade in Services; Overseas Arrivals and Departures (OAD) data; and prices information on the cost of flights.

The value of imports of freight services is derived from the cost, insurance and freight (c.i.f.) measure of merchandise trade statistics, with a minor adjustment made for resident freight operators sourced from the SITS.

The SITS is used to measure all other components of transportation services, except for transportation passenger credits which uses OAD and prices data.

Travel services is broken down to either personal or business purposes. Travel for personal purposes is further broken down into education, health, or other including for holidays.

The major components of personal travel services are calculated as follows:

• Education related travel exports:  calculated using the number of students derived from student visa data supplied by the Department of Home Affairs multiplied by student expenditure derived from Tourism Research Australia’s International Visitor’s Survey (IVS), and fee data supplied by the Department of Education.
• Other personal travel, both exports and imports:  calculated by the number of travellers by reason derived from OAD data multiplied by their expenditure derived from TRA data. Other personal travel imports also uses RBA data on card payments made by Australians while overseas.

Business Travel – exports and imports both use the OAD data for the number of short-term travellers by reason, and expenditure supplied by Tourism Research Australia.

The following outlines the principal data sources and methods for estimates of exports and imports of other services:

• Manufacturing services on physical inputs owned by others:  modelled using data from the International Merchandise Trade Statistics sourced from customs records.
• Maintenance and repair:  modelled using IMTS data.
• Construction services:  estimated using data from the Survey of International Trade in Services.
• Insurance services and pension services:  modelled using data from the Australian Prudential Regulatory Authority; Australian Taxation Office; data on exchange rates from the Reserve Bank of Australia; and the ABS’ financial accounts. 
• Financial services:  modelled using data from the Survey of International Trade in Services; Survey of International Investment; and financial accounts.
• Charges for the use of intellectual property:  modelled using data from the ATO and SITS. 
• Telecommunication, computer and information services:  estimated using data from the Survey of International Trade in Services.  
• Other business services:  modelled using data from the ATO and SITS. 
• Personal, cultural and recreation services:  modelled using data from the ATO and SITS.  
• Government services:  modelled using data from the departments of Defence, Foreign Affairs and Trade and Home Affairs.

Volume measures are obtained mainly by deflation of the current price values, using relevant ABS price indexes underlying those published in:

• Consumer Price Index, Australia;
• Producer Price Indexes, Australia;
• Award Rates of Pay Indexes, Australia up until March quarter 1998; and
• from June quarter 1998, Wage Price Index, Australia.

In most cases, volume measures are derived by deflating current price values using consumer price indexes from overseas countries, adjusted for exchange rate changes.

In other cases, special purpose price indexes, implicit price deflators and ABS price indexes from Consumer Price Index, Australia and International Trade Price Indexes, Australia are used.