APPENDIX 3 SEASONALLY ADJUSTED AND TREND ESTIMATES


INTRODUCTION

Seasonally adjusted and trend estimates add to the understanding of overseas arrivals and departures (OAD) statistics. Seasonally adjusted estimates allow users to analyse short-term movements including irregular impacts on the series, while trend estimates provide a better method to analyse and monitor the underlying direction of the short-term movement series. In most cases the trend series is the best source of information on the long-term direction of these statistics.

The following graphs are provided to illustrate variations in the seasonally adjusted and trend series for selected countries. These graphs cover the ten year period December 1999 to December 2009.


SHORT-TERM VISITOR ARRIVALS

Selected source countries

The graph for Italy shows the large increase in the seasonally adjusted series for short-term visitor arrivals in July 2008, during World Youth Day in Sydney. For Japan, the graph shows the significant impact of Severe Acute Respiratory Syndrome (SARS) on the seasonally adjusted arrivals series in mid-2003. The graph for Vietnam shows the strong growth in the trend series from early 2003 to mid 2008, followed by monthly fluctuations.

SHORT-TERM RESIDENT DEPARTURES

Selected destinations

The graph for Germany shows, in the seasonally adjusted series, the effect of Germany hosting the 2006 FIFA World Cup (9 June to 9 July). For Indonesia the graph shows the introduction of breaks in series due to the reduced level of travel experienced after the Bali bombings of 12 October 2002 and 1 October 2005. Further breaks were inserted in December 2003 and December 2006 as movements returned to levels closer to those recorded prior to the bombings. For residents departing to the United States of America the graph illustrates the effect of the 11 September 2001 terrorist attacks in that country on short-term departures of Australian residents to the United States of America.

With the reintroduction of the trend series for short-term resident departures (see Explanatory Notes, paragraph 25), breaks in series for the following graphs have been inserted from April 2009. These breaks are associated with the increase in movements that coincided with the introduction of initiatives to combat the Global Financial Crisis. For example, the Australian Government stimulus packages of October 2008 and February 2009, and cut-price air fares and travel packages. Additionally, travel from Australia has continued to benefit from the high Australian dollar.