Correlative conjunctions are the conjunctions that work in pairs where both are contributing to connect the words or phrases in the sentence and stabilize the meaning.
As per the given question, the complete correlative conjunction would be 'not only...but also' as it is working in pairs to link or correlate the words and phrases to offer a balanced and cohesive thought. Thus, 'Not only....but also' is the pair of correlative conjunction employed in the sentence.
The following sentence best paraphrases the passage:
"Swift maintains that, if asked, people who have lived in poverty their entire lives would say that they would rather have been sold for food at one year of age."
