Two datasets of world trade flows are available:
1. The newest dataset covers the years 1962-2000, and is constructed from United Nations trade data by Robert Feenstra and Robert Lipsey, under a grant from the National Science Foundation to the National Bureau of Economic Research (NBER). Documentation for this data is included with the files, which are available in SAS and STATA format:
NBER-United Nations Trade Data, 1962-2000
2. An older dataset covers the years 1970-1997, and is constructed by Statistics Canada, who also used the United Nations trade data. The Statistics Canada world trade was purchased and distributed by the NBER under a grant from the National Science Foundation, as described in: Feenstra, Robert C., Robert E. Lipsey and Harry P. Bowen, 1997, "World Trade Flows, 1970-1992, with Production and Tariff Data," NBER Working Paper 5910.
A. The early years of the Statistics Canada trade data, 1970-1979, can be downloaded as ASCII files from:
NBER-Statistics Canada Trade Data, 1970-1979
B. The later years of the Statistics Canada trade data was formerly distributed by the NBER along with the Working Paper 5910, but is no longer distributedby the NBER. Instead, users can obtain the later years (1980-1997) from the University of California, Davis, under a licensing agreement with Statistics Canada. The later years can be downloaded as ASCII files from:
UCD- Statistics Canada Trade Data, 1980-1997
These two sources of Statistics Canada trade data are consistent, and documentation is available at those links.