I have been taught that when creating compound modifiers, a hyphen (-) should be used if the compound consists of two words, while an en-dash (–) is used if the compound consists of three or more words:
I am Vancouver-based journalist.
You are a New York–based journalist.
She is a Rio de Janeiro–based journalist.
I have also been taught that when listing multiple compound modifiers that share a common base(?), one can use a suspended hyphen to avoid repetition:
He is a Canada-, US-, and Brazil-based journalist.
My question, finally, is how these two rules work together. Are the following sentences correct?
I am a New York– and Vancouver-based journalist.
You are a Vancouver- and New York–based journalist.
She is a Rio de Janeiro–, Vancouver-, and New York–based journalist.