Global trade in the 21st century is characterised by complex value chains. Successful exporters usually rely on quality imports, and exported goods cross borders many times before reaching their final consumer. This poses challenges to economic measurement as well as policymaking because it becomes difficult to characterise the true interdependencies between countries. Currently, estimates of the share of imports from a trade partner destined for re-exports, and the share used in the domestic economy, are crude at best. We develop a novel approach to estimate these shares.