[tom-_-]

Close relationships can having negative value and it's apart of the question (see parenthesis). Gaining and keeping a relationship are not the same but also not particularly relevant here since the purpose is to quantify the value of close relationships when making a rational decision. Parent to child, child to parent, spouse to spouse, etc relationships have very different value but if you've never had a child, then your estimations of value can only come from your own relationships or asking other parents.

Wrt to bailing on your child, many single moms and dads will tell you that's a thing, not a noble thing but it obviously happens. Also consider marriage, in the US divorce rates are around 40% and can cost more than half of your total assets, which is often far more than the cost of raising a child. In terms of expected value (depending on your income), more risky to get married than to have a child.