So assuming you agree both parents should contribute, you think it costs in the neighbourhood of $900 a month to raise a kid (excluding all the extra curricular, day care or any other extraordinary expense that would be tacked on as additional payment over and above basic child support)? 

Also, my experience may be with Canadian support, but there is a very narrow range of income that would require support at that amount. And that would be when making in the neighbourhood of $40k a year. 

So you're advocating for discrimination based on public policy concerns, as in exactly what I suggested you were. 

So... now I'm curious what your thoughts are on stop and frisk laws. 

Also, any thought given to what pool of funds cost incurred by a non-custodial should come out of? Like those costs for food, clothing, entertainment, having an additional bedroom that are given no consideration under support tables unless that time exceeds 40 percent of the days in a year? 

Right to keep their breasts hidden on broadcast TV. Men's breasts are able to be showed whenever they want, but for some reason the United States frowns when women show their breasts. Are men and women really equal?

The two are related, but not in the way that you suggest. Stop and Frisk was wrong because it discriminated against people without any actual suspicion that they had done something wrong. The regime of child support payments is wrong only in that it is a one-size-fits-all approach to a problem which is more nuanced, but is superior to the alternative of the legal right-of-surrender, because of how damaging poverty is to a child's development, and the likelihood that single-parenthood is to contribute to poverty.

It is an imperfect system, but not an unjust one, per se.

Making non-custodial parents pay all, or in the majority of cases (in my view, I'm not going to cite studies on the actual cost of raising a child, and they all vary widely) far more than the cost of raising a child from the outset is assuming they won't meet the needs of the child without state coercion. I'm not being sarcastic when I say this, but really in this day the thought a non-custodial parent might be capable and willing to meet the needs of their children without being told/forced to by the state is not in anyone's contemplation. There is an almost society wide assumption that they won't, without giving them any chance to do so. Exactly the same assumed guilt you acknowledge with stop and frisk. Only in the case of racial discrimination most people can't stomach that, but unjustified, outright transfers of wealth from men to women with children is not something that will attract protests. You can suggest a custodial parent may not petition the state for support if it is being made (and I'm sure this happens), but you underestimate the greed of some who see the potential personal gain for themselves that can be realized by enforcing child support laws even if the needs of the child are being met without state intervention. When laws allow for this sort of unilateral choice for exploitation of another they are unjust. 

But when we talk about exploitation, if we define it in terms of "needs of the child," then couldn't a non-custodial parent sue to try and declare that the needs of a child are being met even when they're actually not?

We can agree that the system needs to be refined, but how many cases of abuse are there, in fact? It is one thing to say they exist, it is another to quanitfy them, much like the spurious arguments behind voter ID laws.

I know in Canada that needs are defined by income, and in my experience the child support amounts are even higher in the US. So if for instance you had two parents each making $100k, and they were meeting the needs of the child with $800 a month between them (excluding day care, sports, etc) but the obligation of the non-custodial parent was about $950 according to the tables (before day care, sports, etc.), they would not be able to get around that in any way by suggesting the needs were already met. The custodial parent can have the support enforced at $950, continue meeting the child's needs at $800, save the $150 over and above plus extinguish any financial responsibility for themselves (the previous $400 they were contributing for a net gain of $550 a month). Remember decisions are being made in the context of divorce or separation, so I'll leave you to decide whether these are generally amicable situations.

I'm talking about a hypothetical reform. What would you like to see happen with child-support policies?

Things like what you've mentioned, if you can show needs can be met outside guideline amounts, a court should be willing to allow those amounts. An acknowledgement in the legislation that custodial parents are held to the same support standard as the non-custodial (even if simply stating it won't make a difference). A hard cap on support payments that will never be exceeded outside extraordinary circumstances.

As for any sort of table that would exist, the amounts should be focused on actual costs. On a somewhat funny side note, the local enforcement agency had listed the costs for raising a child on their website in the hopes of compelling payor parents to keep up with the payments. The final amount was either $380 or $480/month or something in that area. They ended up pulling it down quite quickly, as many parents complained they paid more than this per month themselves, and secondly, the implication was that the agency completely forgot about any sort of obligation for the custodial parent to contribute to these costs and portrayed the entire obligation as that of the non-custodial parent (was a bit of an embarrasment).

Would also like to see a debit card system that the support be drawn from over a certain amount. Do not allow cash withdrawals, and give either the paying parent or an oversight agency access to the monthly debits as a basis for any possible complaints on whether the money is supporting the children. Just some ideas off the top of my head, what would yours be?

Do people not think raising a child is also part of the cost? A non-custodial parent is less physically responsible for their children. That has value and is the reason we pay nannies and baby-sitters. Time is money is a saying for a reason. I am sorry but both parents paying an equal share does not sound fair and equal in the least bit.