Methodology and sources

Dataset content: our new estimate of world trade by countries are annual series ranging from 1948 to 2020. We organize the data set by continent and single excel (and txt) files by polities (that is more specific than countries).

Methodology and Sources: On total exports and imports current prices, we use mainly the United Nations statistical databases UNCTADstat and Comtrade. To expand the available sample of polities with constant price series, we construct price deflators for the missing polities. We take representative international prices, when necessary convert them from c.i.f. (cost, insurance and freight) to f.o.b. (free on board) using data on transport and insurance costs, and construct trade deflators using the product composition of imports and exports as weights.The complete methodology followed and sources for each polity estimate is available in the Excell file for every country and the online Appendix here.

Time series coverage:
At current prices series begins with 144 (exports) and 139 (imports) in 1948, rises to 168 (exports and imports) in 1950 and achieves complete coverage only from 2012 onwards. Missing series decline from 25 per cent in 1948, to 14 per cent in 1950, and eight per cent in 1980. By 2000, under one per cent of polities are missing their trade  values. Estimation of the series of trade at constant prices requires the availability of trade deflators. The number of deflators published in the Yearbooks rose from 63 in 1948 to 71 in 1979. The series available from UNCTADstat begins in 1980 with 113, and 97 more countries are added in 2000, bringing the total to 212 for the twenty-first century.