B. Sources for modes of supply data
4.12. When considering sources for modes of supply data, compilers should carefully evaluate how residence is defined in their country, be aware of the laws and regulations for migration and trade in services and assess how such information can be used in a statistical context. Mode of supply data for trade in services can either be collected through direct reporting (surveys) or estimated or modelled. In many cases, a combination of the two approaches should be used to obtain the required aggregates. Using surveys to collect modes of supply data is advantageous in that the compiler has significant control over the data that can be obtained and the surveys can be tailored to answer specific policy questions. Modes of supply data are unlikely to change significantly in the short-term, so the extra questions may not need to be included each time the survey is run. However, the advantage must be weighed against other considerations, such as cost, respondent burden and difficulty in implementing the survey, such as respondents understanding the concepts so that they will report correctly.
4.13. Sources for mode 2 movements of persons are likely the same as those used for the collection of travel information, such as household, border and labour surveys. For incoming mode 2 persons, specific surveys targeting students, medical personnel and tourists could be used in addition to border surveys. Values calculated from household surveys must be accompanied by sufficient metadata since there are likely to be large sample errors associated with such values. Often the data will need to be combined with other sources, such as administrative data on border counts or entry and departure cards, to obtain relevant data on the number of mode 2 movements and persons.
4.14. Regarding mode 4, persons, border and household surveys, enterprise surveys and, potentially, inward FATS surveys (if they include variables measuring exports and imports of services of the foreign affiliate) are important sources both for incoming and outgoing employees and for self-employed persons providing services under a contract. Regarding mode 2, the data will most probably need to be combined, in particular for compiling breakdowns, to obtain relevant data on the number of mode 4 movements and persons, for example through the use of data on characteristics sourced from surveys of persons or households, combined with counts of those crossing borders. Use of data from partner countries may make it easier to capture the relevant information for sending countries.
4.15. For compilers using an ITRS, modelling the relevant mode of supply may be the only option. Data on mode 3 (commercial presence) will need to be collected, in addition to existing data on the resident/non-resident services trade, as that mode of services supply falls outside the scope of service transactions measured under the BOP framework.