The Externality, Not the Sin
Begin with the distinction that every child support debate collapses without. The state has no legitimate interest in a man’s chastity. It has an overwhelming fiscal interest in the internalization of a cost he has externalized onto someone else.
A man who fathers children across multiple households has not committed a crime. He has committed an externality. The children’s housing, food, schooling, and healthcare are real costs. If he does not bear them, the mother bears them, and when the mother cannot, the state bears them, and when the state bears them, the taxpayer bears them. The transfer is invisible because it is distributed across a million budget lines and a generation of underfunded childhoods, but it is a transfer nonetheless. The question of child support is not whether the playboy should be shamed. It is whether the price of his paternity should be set by him, by the mother, or by the state.
The answer is the state, and the instrument is a price, not a prosecution. Criminal sanction is a blunt tool for a civil obligation, and moral condemnation is not a policy instrument at all. What the state should do is bill him—uniformly, per child, in proportion to what he earns, with no cap and no discount for volume.
I. The Cap Is a Subsidy to the Playboy
The most consequential design flaw in most child support regimes is the cap. Above a certain income—or above a certain total obligation—the liability stops rising. The rationale is always some version of “the child does not need more than X.” The effect is different, and it is the opposite of what the state claims to want.
A cap makes the marginal cost of an additional child zero for any father who is already above it. That is the textbook definition of a moral hazard. A man who has already maxed out his obligation faces no additional financial consequence for the next child, the next household, or the next woman. The cap converts his paternity from a priced decision into an unpriced one. The state has not discouraged the behavior it disapproves of. It has subsidized it, and it has done so precisely for the men who can most easily afford to respond to a price.
The law-and-economics literature on marginal deterrence is unambiguous on this point: a sanction that is constant above a threshold provides no incentive to stop at the threshold. A liability that is proportional to income and uncapped at the top restores the marginal price. The rich playboy who impregnates half the village should be paying in proportion to what he has—not in proportion to a schedule that was calibrated for a median earner and then frozen.
II. Why Rich Fathers Ought to Pay More: Three Rationales
The case for progressivity in child support is not envy. It is three separate arguments, and they do not depend on each other.
First, continuity of expenditure. The dominant design principle in modern child support—the “income shares” model used in most US states—holds that the child should receive roughly the same proportion of parental income as they would have received had the parents remained together. The child of a wealthy father is being raised in a housing market, a schooling market, and a healthcare market with high fixed costs. A flat obligation that covers a middle-class childhood leaves the child of a wealthy father with a standard of living that collapses at the moment of separation. The obligation should track the environment the child was actually raised in, not the median environment of the jurisdiction.
Second, human capital. The Becker–Tomes framework is the correct lens. Parental expenditure on children is an investment in human capital, and the return on that investment is not linear in the amount spent. The marginal euro of a high-income father buys more schooling, better nutrition, more stable housing, and thicker networks than the marginal euro of a low-income father. The social return on the transfer is higher, not lower, at the top. A child support schedule that caps the wealthy father’s contribution is a schedule that underinvests in the children with the highest expected return.
Third, deterrence. This is the one that connects back to the playboy. A proportional, uncapped liability makes the marginal cost of additional paternity real for the men who face it. A capped liability makes it trivial. If the state’s objective is to reduce the number of children born into externalized-cost households—and it should be, because those households are where the poverty is concentrated—then the price has to bite at the top of the distribution, not just the bottom.
III. The Volume Discount: How Guideline Schedules Reward the Repeat Father
There is a second design flaw, subtler than the cap, and it operates in the same direction.
Most guideline schedules are concave in the number of children. A typical US state might set the obligation at 17% of income for one child, 25% for two, 29% for three, and 31% for four. Each additional child raises the total obligation—but by a smaller increment than the one before. The marginal rate per child falls as the number of children rises. The multi-family father is receiving a volume discount.
This is exactly backwards if the objective is marginal deterrence. A flat per-child percentage—each child receives X% of income, so five children receive 5X%—would give a constant marginal cost per child. A schedule that rises with the number of children would give an increasing marginal cost, which is what a serious deterrence regime would look like. The concave schedule does neither. It gives the repeat father the cheapest marginal child in the system.
The reform is simple and it follows from the principle: the obligation should be linear or convex in the number of children, not concave. Each child is a separate claim on the same income. The Nth child should cost at least as much as the (N−1)th, not less.
IV. Why the Progressive Tier Must Be Thresholded High
Here the argument turns, and it turns on arithmetic rather than sentiment.
The case for progressive child support at the top is sound. The case for making the entire schedule progressive—steep rates from the first euro—is not. And the reason is the composition of the fertility base.
The modal father is working or middle class, not rich. In any society with a roughly lognormal income distribution, the aggregate number of children is dominated by the mass of households in the middle of the distribution, not the tail. The top decile is 10% of households. Even if high-income men have above-average fertility—and in many above-replacement societies they do—they cannot dominate the birth cohort, because there are not enough of them. The children are sired by the 50th to 90th percentile. The demographic research on the status–fertility gradient points in the same direction: in high-fertility settings, fertility is concentrated among the less educated and the rural, and the middle of the distribution carries the bulk of the births.
That has three consequences for design.
The first is that the revenue base is in the middle, not the tail. A schedule that squeezes the middle aggressively raises more revenue than a schedule that squeezes the tail aggressively, because the middle is where the cases are. The top tier is a small number of high-value cases; the middle tier is a large number of moderate-value cases. Any collection agency will tell you that the yield is a product of cases × average liability × compliance rate, and the middle wins on cases even when it loses on average liability.
The second is that the compliance base is in the middle, and it is fragile. The working-class father has irregular earnings, a new household of his own, and a marginal tax-and-obligation rate that can already exceed 60% when child support, tax, and benefit withdrawal are stacked. Push that rate higher and he does not pay more. He goes informal. He works cash. He disengages from the formal labor market entirely, and the obligation becomes uncollectable. The empirical literature on low-income non-resident fathers is consistent on this: they contribute in cash and in kind, irregularly, outside the formal system, and a system that demands a formal percentage of a formal income simply prices them out of compliance.
The third is that the very rich are the most avoidable cases. High-income fathers have the most access to income-shifting: self-employment, corporate structures, deferred compensation, offshore arrangements, and the simple option of reporting a lower income. The per-case yield is high, but the compliance rate is the lowest in the distribution. This is precisely why tax administrations around the world concentrate enforcement in large-taxpayer units—not because the rich pay the most in aggregate, but because the yield per unit of administrative effort is highest where the liability per case is largest.
The design that follows is not flat, and it is not uniformly progressive. It is a moderate, predictable, flat-ish base rate for the mass of fathers, with a steep progressive surcharge only above a high threshold. Set the surcharge at the top decile of male earnings, or the top 5%. Below it, the rate should be low enough that the working-class father stays in the formal economy, indexed to actual earnings, and forgiving in months of unemployment. Above it, the rate should be steep, uncapped, and enforced with the full apparatus of the state—because the number of cases is small, the yield per case is large, and the avoidance cost is high enough that the effort pays.
The threshold is not a concession to the rich. It is a concession to the arithmetic. The progressivity has to be concentrated where it actually bites, and the base has to be kept broad and compliant where the children actually are.
V. The Nordic Solution: Guarantee the Child, Recover from the Father
There is a design that resolves the enforcement problem entirely, and it is already in operation.
In Finland, the child’s maintenance is not held hostage to the father’s compliance. Kela—the Social Insurance Institution—pays a child maintenance allowance of €197.71 per month per child as of January 2026 when the liable parent fails to pay the court-ordered amount. The state then recovers from the father. The child’s income is secured first; the father’s obligation is enforced second.
This is the correct ordering, and it is correct for a reason that has nothing to do with generosity. It moves the risk of non-payment from the child to the state, and the state is the only actor with the enforcement apparatus to bear it. It also aligns the state’s incentives with collection: once the state is paying the allowance, it has every reason to pursue the father, because every euro recovered is a euro returned to the treasury. The recovery schedule can then be as progressive as the state likes without harming the child, because the child’s income is already guaranteed.
The Nordic model also makes the thresholding argument easier to implement. The guaranteed minimum is universal and modest. The recovery schedule is where the progressivity lives, and it can be tiered by income without any risk that a high earner’s avoidance strategy starves a child. The child is paid. The father is billed. The two are decoupled.
VI. The Working-Class Father Is Not the Problem
The moral framing of child support policy treats the “deadbeat dad” as the modal non-resident father. He is not. He is the tail, and the tail is the part the system is worst at collecting from.
Edin and Nelson’s Doing the Best I Can is the canonical ethnography, and its finding is not that low-income fathers are indifferent to their children. It is that they contribute—in cash, in kind, in childcare, in irregular lump sums—outside a formal system that cannot see their income and cannot accommodate their volatility. A system that demands a fixed percentage of a formal paycheck from a man whose pay is irregular will collect nothing from him and will drive him further into the informal economy where it can collect even less. The compliance problem at the bottom is not a moral problem. It is a measurement problem, and the measurement problem is solved by forgiving the base, indexing to actual earnings, and keeping the marginal rate low enough that staying formal is worth his while.
The working-class father is also, in the aggregate, the father the state should be rewarding, not squeezing. He is the one raising children inside a two-parent household in most cases, and when he is not, he is the one whose children are most likely to be the next generation of taxpayers. A child support regime that treats him as the primary target is a regime that has misidentified the population it is trying to reach.
VII. The Village Revisited
Return to the framing. In an above-replacement society, the man who fathers many children is not producing a fiscal drain. He is producing the tax base. The externality is not “too many children”—it is externalized cost. The mothers bear the cost, the state absorbs the shortfall, and the father is priced out of the transaction by a cap, a concave schedule, and a compliance regime that cannot see his income.
The remedy is not a prosecution and not a moral panic. It is a price, set correctly:
- No cap. The obligation rises with income, without a ceiling.
- No volume discount. The schedule is linear or convex in the number of children, so each additional child costs at least as much as the last.
- A high threshold for the steep tier. The mass of fathers is working and middle class, and the base has to stay broad, formal, and compliant. The progressivity belongs above the top decile, where the yield per case is large and the avoidance cost is high enough to justify the enforcement effort.
- A state guarantee. The child is paid first, and the state recovers from the father second. The child’s welfare is never contingent on the father’s willingness.
The Bottom Line
The state should not punish the playboy. It should bill him—per child, proportionally, uncapped, and with no discount for volume. A cap is a subsidy to the behavior the state claims to disapprove of, and a concave schedule gives the repeat father the cheapest marginal child in the system.
Rich men ought to pay more, for three independent reasons: the child’s standard of living should track the household they were raised in, the marginal euro of a high-income father buys more human capital, and a proportional liability is the only one that makes the marginal cost of additional paternity real at the top of the distribution.
But the progressive tier must be thresholded high, because the arithmetic of the fertility base is unforgiving. In above-replacement societies the children are sired by the working and middle class, and a schedule that squeezes the mass of fathers extracts little revenue, drives them into the informal economy, and collects less than a moderate base rate would have collected from a compliant majority. Concentrate the progressivity where the cases are few, the yield is large, and the avoidance cost is high. Keep the base broad, formal, and forgiving.
The child is guaranteed. The father is billed. The price is set at the top and the compliance is maintained in the middle. That is not a moral program. It is a collection strategy, and it is the only one that survives contact with the numbers.
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