...
1.7. Existing statistical frameworks can be used as a basis for the production of data to satisfy the information needs of GATS regarding modes of service supply. For example, the value of the international supply of services of a country can be established once statistics on the output of foreign controlled affiliates have been developed for the services sector to accompany the balance of payments (BOP) services statistics. The combination of both data sets would cover all four modes, provided that compilers ensure that appropriate breakdowns are delivered (i.e., service type, mode of supply, partner country and exchanges between related and unrelated trade). As MSITS 2010 explains, to produce a complete picture of the international supply of services, additional data, including both monetary and non-monetary indicators, are still necessary.
...