UNCTAD collects data through national compilers (such as central banks, various ministries, statistical offices, etc). Data sources for FDI and TNCs include balance of payments statistics, business registers and enterprise surveys. These are complemented by corporate reports and information from the press.
In the absence of primary sources, UNCTAD uses data from regional, international organizations or research institutions. Data are updated on an on-going basis, depending on data availability and resources.