16.2. While most of the present Guide provides good practices for obtaining the value of the international supply of services (i.e., the value of trade in services or sales/output of services of affiliates), trade negotiators and analysts need additional information on the market performance of individual service sectors, such as foreign direct investment flows and stocks, research and development expenditure in affiliates and income flows relating to foreign affiliates active in services sectors. In the same way as there is interest in the monetary and non-monetary measures of merchandise trade, non-monetary information drawn from various quantitative indicators is also important for assessing trade commitments and for conducting further in-depth analysis on the international supply of services (e.g., number of modes 2 and 4 persons, number of foreign affiliates established abroad in the context of mode 3, etc.).
16.3. The present chapter aims at presenting such additional data items, many of which are already defined within other statistical frameworks and may be extracted without additional cost if the level of detail needed is readily available (i.e., the frameworks for FATS, FDI statistics and sectoral statistics, e.g., tourism and education). Such additional data items will be further detailed in section E. Linking trade and business registers is also a new line of work that compilers should be aware of, given the potential that such an exercise offers for compiling new sets of data of interest to policy makers with little additional effort or cost (section D).
16.4. However, meeting user needs requires the development of new data compilation systems, or the extension of existing ones. For example, in the case of mode 2, information on the number of persons/trips (section C.2) travelling abroad and consuming services, whether for personal or business reasons, is in high demand. Such extension is even more valid for a variable of greater interest to negotiators and analysts: the number of persons moving to provide services under arrangements covered by mode 4 (section C.1).
16.5. Knowing how many people are providing services abroad (flows and stocks and the number of associated trips) is very important for analysis of both GATS and international mobility. First, as stated above, as for merchandise trade, non-monetary (quantitative) statistics may usefully complement value data about the mode 4 supply of services. Second, given the interest that mode 4 generates among officials and research institutions involved in the international supply of services and/or migration issues, quantitative data provide a useful gauge of the relative importance of mode 4 movements of persons within wider economic international mobility. That is why the present chapter focuses particularly on mode 4 number of persons and trips. The chapter identifies sources that could be used and elaborates how relevant statistics could be produced. In the context of mode 4, a subset of the population of business travellers will be of particular interest, but other categories of internationally mobile individuals will also be relevant.