tax collection vs collecting

tax collection and collecting both are nouns.

Word	Noun	Adjective	Verb	Adverb
tax collection	Yes	No	No	No
collecting	Yes	No	No	No

As nouns, collecting is a hypernym of tax collection; that is, collecting is a word with a broader meaning than tax collection:

Other hypernyms of tax collection include aggregation, assembling, collection.

tax collection (noun)	collecting (noun)
the collection of taxes	the act of gathering something together