Swift's famous essay takes a contemporary issue--the Irish Famine--and the British government's response to it and then satirises the situation in his treatise by assuming the voice of a statistical planner. You might want to think about the number of times that statistics are referenced. Consider the following example:
I have reckoned upon a medium, that a child just born will weigh twelve pounds, and in a solar year if tolerably nursed increaseth to twenty-eight pounds.
Note how Swift makes every effort to present himself as a reasonable, logical man who has thought through his sums with great care, even trying to establish a "medium" of a baby's birth weight. We need to be aware of the wider implications of what Swift is satirising. He is not just trying to satirise the response of the British government--he is also protesting against a view of humanity where humans are treated as numbers and mothers to "breeders" and babies to a food source. Swift's satirical method is to make himself appear as the most chilling, cold-blooded monster possible so as to reveal similar attitudes in his audience.