The Microeconomics of Child Support

I was recently fortunate enough to do some work experience for a judge. As well as seeing some of the dramatic debates that one imagines taking place in court, I saw some of the smaller scale judgments that are made at tribunals. Primarily these were in relation to child support; either a parent with custody appealing that the specified level of child support was too low, or a parent without custody appealing that the specified level of custody was too high. In the cases that I saw all the parents with custody were mothers.

The first thing that struck me was the extent to which fathers went out of their way to avoid paying child support. Of course, this was clearly partially a result of the selection effect; the people at the tribunal were the select few trying to avoid paying. Nevertheless, there was an example of a mother suing a deceased father's estate for unpaid child support; their daughter was not a beneficiary of the estate at all. Surely, however much parents may come to hate each other, they would not go so far as to prevent their children from receiving money after their death?

However, once I thought about it, I realised that they might reasonably see child support going not primarily to their child but to their ex-spouse. Consider an imaginary example in which a father is ordered to pay £200 weekly to a mother with custody. It is essentially a transfer from the father to the mother to compensate her for the child's expense. One might reasonably expect that the mother will spend some of the money on the child, but it seems unlikely that it will be spent exclusively on the child. To think of it in another way, if the mother was made £200 poorer she would not reduce spending on the child by £200; she would seek to cushion the drop in income by reducing some of her own expenses. In fact, it seems likely that, given that in most cases the mother will already have bought the child the things which she deems necessary for their happiness, a significant portion of the money will essentially recompense her for this expense rather than be used for additional spending on the child.

Now, it is quite likely that the child support will not pay for half of the costs of bringing up the child (especially if one values the mother's time, too). As a transfer, it seems more than fair. Nevertheless, from the perspective of a father who hates the mother, one can see why he might be reluctant to pay child support even if they wish their child well. This doesn't excuse their behaviour, but it does begin to better explain some of it.