Our 2017 JCR paper with Tyson Chatagnier uses a measure of export similarity between countries for the years 1962-2000. In February 2023, we updated this measure and extended it to 2020.
Note that this version is based on the Atlas of Economic Complexity whereas the original version was based on the World Trade Flows data. The two measures are highly correlated (0.92).
You can find the updated measure [HERE].
You can find the original measure in the [2017 JCR replication file].