According to A Modest Proposal's narrator, Ireland's poor adults would be able to earn a living if they fattened and sold their one-year-old babies to the rich as gourmet food. The narrator then gives detailed calculations to show that doing this would be profitable for the poor, noting that it would cost a mother only two shilling to raise a "fat" baby for a year, including the cost of dressing it in rags. The baby could then be sold for 10 shillings, leaving the mother a profit of eight shillings. A "thrifty" mother could earn even more if she turned the skin of the baby into gloves or shoes.
In addition, the poor would have "something of their own" (the babies) which could be seized to settle debts. Further, killing many of the poor at a year old would reduce the number of the impoverished children and adults needing to be supported by charity, which would free up the money to increase Ireland's wealth. Finally, the money earned from this trade would stay in Ireland, people would be encouraged to marry because of the profitable baby selling business, and more people would come to eat in the taverns if they knew they could purchase such a delicacy.
Swift meant for people to be horrified by his narrator's idea. The essay satirizes (uses humor and exaggeration) to expose the cruelty in treating people as if they have no value beyond how much money they are able to earn.