Asymmetries in statistics on International Trade in Goods
A good understanding and overview of the nature and major sources of the data errors were obtained from structured in depths microlevel analysis involving a lot of correspondence with colleagues from 6 different EU National Statistical Offices and to some extent local importers/exporters.
https://www.dst.dk/en/consulting/news-from-international-consulting/2021/19-10-2021-asymmetries-in-statistics-on-international-trade-in-goods