There can be many reasons for making this decision, but a recent driver of the high number of unaccompanied children arriving at the border was the Title 42 Policy. While family units were turned away under this public health order, unaccompanied children were exempt, which created an incentive for parents to send their children alone so that they would not be turned away.
It’s also important to note that every family has a different situation, and in many cases, the parent is not sending the child across the border at all. Not all of the children legally deemed by CBP agents as “unaccompanied” arrived at the border alone. If a child is apprehended at the border with a family member who is not their parent or legal guardian (such as a grandparent or an aunt), they are separated from that person and deemed “unaccompanied.” In some cases the children embark on the journey alone or in groups in an effort to reunite with their parents who are already in the United States. According to ORR records from 2019, 86% of unaccompanied children arrived when they were between the ages of 13 and 17.