By a hierarchy, we mean a system of concepts where each has zero or one parents and zero or more children. The root, or top concept, has no parent; the leaves, or bottom concepts, have no children; and the rest have one parent and one or more children.
In "zero or one parents", "parents" should read "parent"
When a major version of a classification follows another, the statistical agencies usually have to know how the items of the previous version have evolved under the new version: this is important for the continuity of times series, indexes, national accounts, etc., to give a few example.
"Times series" should read "Time series"
The economic classifications forming this system are linked either by a common structure which is more and more detailed from the international to the European then national levels, or by semantic correspondences between the economic fields covered: activities, products and goods (e.g. activities create products).
"Then" should read "Than"
"Correspondance" should read "Correspondence" (two occurrences on the page)
By a hierarchy, we mean a system of concepts where each has zero or one parents and zero or more children. The root, or top concept, has no parent; the leaves, or bottom concepts, have no children; and the rest have one parent and one or more children.
In "zero or one parents", "parents" should read "parent"
When a major version of a classification follows another, the statistical agencies usually have to know how the items of the previous version have evolved under the new version: this is important for the continuity of times series, indexes, national accounts, etc., to give a few example.
"Times series" should read "Time series"
The economic classifications forming this system are linked either by a common structure which is more and more detailed from the international to the European then national levels, or by semantic correspondences between the economic fields covered: activities, products and goods (e.g. activities create products).
"Then" should read "Than"
"Correspondance" should read "Correspondence" (two occurrences on the page)
Broken link:
The European view of this system is well described in the online publication of the NACE Rev. 2 (chapter 1.1). : http://ec.europa.eu/eurostat/cache/ITY_OFFPUB/KS-RA-07-015/EN/KS-RA-07-015-EN.PDF
Correct link:
http://ec.europa.eu/eurostat/product?code=KS-RA-07-015&mode=view