3.97. The focus of the present IRTS 2008 Compilation Guide is on helping countries implement the IRTS 2008 and develop their national STS frameworks. Consequently, the data to be obtained should be classified using reference classifications (see Chapter V) to help countries pursue both specific national purposes (the collection of much more detailed data) and international comparability.
3.98. Regarding international comparability, the data set and indicators for inbound tourism presented in Table III.2 below will be requested annually by UNWTO from member and non‑member countries and disseminated in the Compendium of Tourism Statistics, its most comprehensive statistical publication.
3.99. As a first approximation for tourism expenditure data, a country can use Balance‑of‑Payments data (“travel” and “passenger transport” items). This ensures a high degree of international comparability. Indeed, the expenditure data included in the UNWTO Compendium are actually taken from the Balance of Payments. The Balance of Payments data are not tourism data per se; rather, they are used to approximate expenditure in the absence of tourism expenditure statistics (for the relationship between tourism statistics and the Balance of Payments, see IRTS 2008, paras. 8.10-8.25).
3.100. As countries successfully develop their own measurements of tourism expenditure, it is expected that this approximated information will be replaced with data on actual tourism expenditure (separately identifying expenditure on international transportation).
Inbound tourism: example of a table of results
“US$ Mn: millions of United States dollars
3.101. Apart from the data and indicators requested by UNWTO, countries are encouraged to generate and disseminate additional information useful to key tourism stakeholders (see para. 1.29), including:
3.102. In the case of statistics on inbound tourism, and also on outbound tourism, it may be useful ‑and user friendly‑ to produce tables of results and disseminate data together with Balance‑of‑Payments data.
 The statistical unit is the trip: the term “visitor” really refers to a tourism trip and the term “traveler” refers to both tourism and non‑tourism trips. However, the number of “non-tourism” trips will be not only difficult but prohibitively expensive to measure.