To fully decompose the value added of the iPhone, and ascribe it to individual countries therefore, one cannot
rely on a list of component suppliers. Information on all of the suppliers and their suppliers, and their suppliers’
suppliers, and so on, is needed. What is needed therefore is a dataset that is able to link production processes within
and across countries; in other words a set of international input-output tables with bilateral trade links (a global input-
output table). Naturally, input-output tables developed by statistical offices aggregate firms into groups (sectors) of
firms that produce similar products, and, as such, input-output tables will not be able to reveal the total domestic value-
added generated by the production of an iPhone in any country. However they will be able to provide such estimates
for the whole economy and indeed by the sectors.