Is it appropriate to omit an auxiliary verb in this case?

In the statement:

Exports are a virtue and imports are a vice

Would it be okay to omit the second "are"? Thus becoming:

Exports are a virtue and imports a vice

If it was grammatically incorrect, I wonder if it is still appropriate to omit the verb in a formal setting. I feel like the latter way of phrasing the sentence rolls off the tongue better.

Solution 1:

Yes. V-deletion is quite common, especially with conjunctive clauses.

Consider:

(1) I like milk and bread

(2) Someone will be happy and generous.

Closer to your example:

(3) My dog is a canine and my cat a feline.

That being said, since 'imports' is a verbal noun, it is best to retain the verb. The ambiguity of 'imports' - the ambiguity between a NP reading and a VP reading - makes parsing quite difficult. Syntactically, the issue is that 'imports' might be read as a present verb whose argument is the clause preceding the conjunction: 'exports (which are virtuous) import (x)'. So best keep the verb.