The Observatory of Economic Complexity combines a number of international trade data sets, including data from Feenstra, Lipset, Deng, Ma, and Mo's World Trade Flows: 1962-2000 dataset,[1] cleaned and made compatible through a National Bureau of Economic Research (NBER) project and HS4 aggregated from the HS6 classification cleaned by the BACI team at Centre d'Etudes Prospectives et d'Informations Internationales (CEPII).[2] The dataset contains exports and imports both by country of origin and by destination. Products are disaggregated according to the Standardized International Trade Code at the four-digit level (SITC-4) and the Harmonized Systems at the four digit level (HS-4).