Joint Custody: Bonding and Monitoring Theories

Margaret F. Brinig & F.H. Buckley⁽¹⁾

Introduction

Like everything else in divorce, custody often seems a zero-sum game in which one spouse wins and the other loses. Time enjoyed with children, which used to be shared, must now be divided. Traditionally, the division was a very sharp one, with one parent awarded sole custody and the other restricted to circumscribed visitation rights. More recently, however, joint-custody awards have become more common. Under joint custody, parents share access to children and child-rearing responsibilities.

Proponents of joint custody argue that it eases the pain of divorce for children. For the child, sole custody may seem like the death of the noncustodial parent, and in many respects it is just that. The child will lose his guidance and emotional support, and not infrequently his financial support as well. Joint custody, though by no means as beneficial for the child as a continued marriage, eases these burdens, and better prepares the child for life as an adult.

This Article discusses two possible benefits of joint custody. Under bonding theories, fathers permit themselves to grow more attached to children when they do not fear a complete break with them on divorce. With the increased emotional ties, divorce becomes less likely. This greatly benefits children, as divorce is one of the greatest tragedies which can befall them.

Under monitoring theories, joint custody addresses an agency-cost problem that arises under sole custody. The noncustodial parent cannot easily see how his financial contributions are spent, and therefore assumes the risk that some moneys will be misspent. With joint custody, by contrast, the parent can monitor for such problems through his increased access and responsibility.⁽²⁾

We tested bonding and monitoring theories of joint custody through regression analysis. We first regressed divorce levels on joint custody and socioeconomic predictors, and found that joint-custody laws are significantly correlated with lower divorce rates, as predicted by bonding theories. We then regressed child-support-payment ratios on legal and socioeconomic predictors, and found that joint-custody laws are significantly correlated with higher child-support ratios, as predicted by monitoring theories. These results are robust under various estimation techniques and different independent variables.

We do not suggest that our findings are dispositive. More research is needed on the relation between joint-custody laws, child support, and divorce. In addition, the reduction in divorce levels may not be benign if wives stay in abusive relationships lest they lose partial custody of their children under joint custody. This too suggests an agenda for further empirical research.

Part I of the Article describes the evolution of custody law, and the recent move to joint custody. Part II discusses criticisms of joint custody, and Part III offers a bonding and monitoring defense of it. Our empirical tests are described in Part IV, and we conclude in Part V.

I. The Law of Joint Custody

On divorce, child custody has traditionally been granted to one parent only.⁽³⁾ Who that parent might be changed over time. Before the nineteenth century, custody was usually awarded to the father, even when he had committed the marital fault.⁽⁴⁾ This changed in nineteenth-century America, and courts began to award custody to the mother when the father was at fault, on the theory that the children would be "best taken care of and instructed by the innocent party."⁽⁵⁾ In most cases, this meant that custody was awarded to mothers. No-fault divorces were not then available, and divorcing fathers usually admitted fault to procure the divorce.

In this century, custody was awarded to mothers for a further reason, as the focus shifted from parental fault to the interests of the child. A "child of tender years" would need a mother more than a father. When the child was very young, therefore, mothers were usually granted custody, to permit the child to receive "such care, love, and discipline as only a good and devoted mother can . . . give."⁽⁶⁾ In time, divorce laws were amended to provide that custody should turn on "the best interests of the child."⁽⁷⁾

While the "best interests" standard at first resulted in a presumption of maternal custody, it later came to mean something very different. Courts came to aim directly at the best interests of the child, without applying any presumptions about which parent should get custody. The presumption of maternal custody was seen as antiquated, and most state divorce laws were amended to remove it and make custody gender neutral.⁽⁸⁾ A minority of states have since moved to a primary-caretaker rule, which awards custody to the parent who had the primary responsibility for the child during the marriage.⁽⁹⁾

At the same time, other family-law changes advantaged erring husbands. In Orr v. Orr⁽¹⁰⁾ the Supreme Court held that sex-based custody preferences in alimony were unconstitutional.⁽¹¹⁾ Alimony came to be seen as a temporary relief measure for divorced wives who would soon become self-sufficient as well.⁽¹²⁾ Divorcing husbands were further advantaged by no-fault divorce laws, which dispensed with fault requirements on divorce. In a fault regime, the party seeking a divorce (often the husband) must offer a side payment to his spouse if he was at fault. Because fault is penalized in this way, there will be less of it, and fewer divorces than under no-fault.⁽¹³⁾

The move to joint custody, which has become much more common in the last twenty years,⁽¹⁴⁾ has also been seen to advantage husbands. Currently, courts in virtually all states are authorized to consider joint-custody arrangements,⁽¹⁵⁾ and nearly a quarter presume that this will be in the child's best interests.⁽¹⁶⁾ Since wives were more likely to be granted sole custody under the primary-caretaker rule, the move to joint custody means that husbands (wives) on average see more (less) of their children after divorce.

Joint custody means more than a sharing of physical custody, as parents must share the responsibility for the child's upbringing.⁽¹⁷⁾ Both parents are to be consulted on major decisions, and each might veto the other's decisions. This contemplates a cooperative relationship after divorce and also means that a husband who pays child support can better see how his money is spent under joint custody.

TABLE I. State Joint-Custody Laws

Year of Enactment of Joint-Custody Statutes, or Adoption by Case.

States which had not enacted such laws by 1993 are denoted by a 0.

Table I lists the states which promote joint custody, and the year in which such laws were adopted. When a state mentions joint custody as an option, we deem it to be a joint-custody state, since courts in all such states appear ready to grant joint custody.⁽¹⁸⁾ Where the statute does not refer to joint custody as an option, but reported cases support such awards, we also list the state under the joint-custody column. On this definition, virtually all states are joint-custody states today, but many were not during the earlier period of our study.

II. The Critique of Joint Custody

This Part considers three objections to joint custody. First, it is said to harm children because custody might be shared with unfit fathers. Second, joint custody is said to effect a wealth transfer from women, who will trade off assets for increased access to their children. Third, the move to joint custody might have no effect on actual custody arrangements when the parties bargain around the legal rule.

These objections raise empirical issues which are beyond the scope of this paper. As such, we cannot assert that the move to joint custody is necessarily benign. However, some of the objections seem less than compelling to us, while the advantages to joint custody which we discuss in the next Part seem somewhat persuasive.

A. The Efficacy of Judicial Screening

Some feminists argue that joint custody ill-serves children. In the move from maternal custody, it is said, fathers who really did not want to raise their child have been awarded joint custody.⁽¹⁹⁾ The move to joint custody has also been seen as unfair to women. In the stress on the child's well-being, the mother's contributions during marriage are devalued. The father's newfound interest in child rearing is heralded and welcomed, while the more faithful mother's longtime contributions are ignored.⁽²⁰⁾ More radical feminists see joint custody as a tool to control former wives.⁽²¹⁾ The debate is often highly politicized, and joint custody is indeed strongly supported by a fathers' rights movement.⁽²²⁾

No one would want to award joint custody to an unfit parent, and there is evidence that children whose parents have been involved in violent conflicts may fare better on divorce.⁽²³⁾ Courts in joint-custody states are therefore enjoined to award sole custody to the fit parent in such cases.⁽²⁴⁾ To the extent that this objection is telling, it raises a concern about the efficacy of judicial screening. If courts can always spot the unfit parent, the problem does not arise. But of course judicial screening is never perfect, and in some cases a joint-custody award might not be in the child's best interests. As well, the fear of such an award might deter a risk-averse wife from leaving an abusive relationship.⁽²⁵⁾ During marriage she can monitor her husband's behavior to the child; after divorce she cannot do so as easily unless she has sole custody.

These concerns suggest a useful empirical agenda.⁽²⁶⁾ However, it is wrong to conclude that screening problems occur only under joint custody. Courts may also err under sole custody, and award exclusive custody to an unfit parent. There is indeed little reason to think that these problems are more severe under joint than sole custody. We might fear a grant of joint custody to unfit fathers if male family-law judges, under the grip of a humanist ideology, systematically favored men. But can anyone seriously think that this describes family-law courts in America? Moreover, given the better monitoring available through shared custody, joint custody's self-correcting tendencies are plausibly stronger than those of sole custody.

B. Wealth-Transfer Effects

The rise of joint custody may also disadvantage women in their property negotiations.⁽²⁷⁾ On divorce, the parties might trade off property for custody.⁽²⁸⁾ Under a sole maternal-custody default rule, for example, a devoted father might offer a greater share of his property for increased access to his child. Alternately, under joint custody, a wife might trade off property for sole custody, if she values sole custody more highly than her spouse values joint custody. Even if both regimes are valued equally, the change from a maternal-custody regime to joint custody might advantage men if women are systematically more risk averse than men.⁽²⁹⁾ Joint custody has also been said to harm women who participate in divorce mediation. Given the option of joint custody, mediation encourages women to sacrifice the economic leverage a sole-custody regime gives them.⁽³⁰⁾

Even if wealth-transfer effects are anticipated, however, they would seem better addressed through stronger property entitlements, assuming that joint-custody rules are otherwise benign. On a move to joint custody, wives might be offered a greater share of the matrimonial assets if the couple has a child. Wives might further be advantaged in property negotiations if no-fault laws are relaxed and property and support duties are made to depend on marital fault, as we have elsewhere proposed.⁽³¹⁾

C. Coasian Irrelevance

Custody laws might be trivial, in the sense that they do not determine who raises the child. This is just what the Coase Theorem would predict: Legal rules do not affect outcomes when the parties can bargain around the rules.⁽³²⁾ If so, the move to joint custody might have wealth-transfer effects, but will not affect actual custody arrangements. The child will always end up with the parent who values him most.

Whether joint-custody laws are Coasian is an empirical question. There is some evidence that couples awarded joint custody settle into custody patterns not unlike those under sole custody.⁽³³⁾ However, the empirical issue is by no means settled. Moreover, as a theoretical matter, the Coasian critique might fail in several ways. First, even parents of ordinary delicacy might be unwilling to treat their children as fungible with money in bargaining over custody. One reason for this is that the willingness to "sell" one's child might be taken as a signal of parental unfitness.

Second, even if parents do bargain over custody, it is not clear that such bargains would be enforced by courts. For example, the bargain's signal of parental unfitness might be taken by a court as a reason to deny custody. Moreover, some courts in sole-custody regimes simply frown on joint custody, even if the parents appear to have agreed to it.⁽³⁴⁾ As well, private joint-custody agreements would contain terms which courts would not enforce. Fathers seek more than time with their children. They also seek the recognition that they have an important role to play after divorce, and a continued right to influence their children's lives.⁽³⁵⁾ Unlike fathers with mere visitation rights, joint-custody fathers must be consulted in all important decisions involving their children. They have access to medical and school records, and are entitled to attend school conferences and all other major events in their children's lives. These privileges follow from the status of joint custody, and cannot be purchased in an enforceable bargain.

Third, attitudes to children might in part be shaped by the legal regime, as a consequence of the custody award's wealth-transfer effects. The claim that custody laws are trivial assumes that preferences for children are exogenous, and unaffected by the custody regime. But preferences might be endogenous, and partly determined by the award of custody.

This might happen when the mother's willingness to pay for sole custody in a joint-custody regime is less than what she would accept in agreeing to joint custody in a sole-custody regime.⁽³⁶⁾ Suppose that (1) the mother's initial endowment of assets is $10,000 and her access to credit is constrained, (2) under sole maternal custody, she would not agree to share custody for less than $50,000, and (3) the father places a value of $20,000 on joint custody. Under sole custody, the parties will fail to reach an agreement, since the mother values sole custody more than the father values joint custody. Thus the child will remain under the mother's sole care. The parties will also fail to reach an agreement under joint custody, since the father will not surrender joint custody for less than $20,000, while the mother cannot raise more than $10,000 for sole custody. The award of joint custody will then remain undisturbed, and Coasian irrelevance will fail to hold.⁽³⁷⁾

Seeing more of their children under joint custody, the fathers might feel greater affection for them, and be more willing to spend time with them. By contrast, the noncustodial father not infrequently loses interest in the child.⁽³⁸⁾ Noncustodial fathers often disengage from their children after divorce, and instead devote themselves to new children acquired through cohabitation or remarriage.⁽³⁹⁾

The change in the legal regime might have affected bargaining behavior in another way. When joint custody was uncommon, fathers did not seek custody, and women were regarded as poor mothers if they did not do so.⁽⁴⁰⁾ The change in social norms has increased the demand by fathers for joint custody, and may in part have resulted from a change in legal norms. Changes in legal rules have been said to affect social norms in such matters as racial discrimination and seat belts,⁽⁴¹⁾ and may also have changed parenting norms.

III. The Defense of Joint Custody

This Part describes how joint custody might benefit children. If the move to joint custody does affect actual custodial arrangements, children might benefit both before and after divorce. Before divorce, the prospect of joint custody might reduce a father's fear that he will lose access to his child. He might therefore invest more emotion in his child, and increased paternal bonding may reduce the possibility of divorce. After divorce, fathers might provide better emotional and financial support for their children when custody is shared. Even if a move to a joint-custody regime does not affect actual custodial arrangements, it gives noncustodial parents a greater ability to monitor how their child-support payments are spent. Monitoring theories therefore predict increased child-support levels under joint custody.

We test bonding and monitoring theories of joint custody in Part IV.

A. Benefits Before Divorce: Bonding Theories

When divorce is not a final separation, fathers may permit themselves to bond more closely with their children. In bonding more closely with their children, they will also bond more closely to their wives, since family affections are not contained in watertight compartments. Fathers might also feel more willing to bond more closely to their wives during marriage when they anticipate continued ties through joint custody after divorce.

For economists, bonding (or "hands-tying") strategies are devices which a bargainer employs to signal that he will perform his promises, when they cannot be legally enforced or when legal enforceability offers inadequate incentives to perform.⁽⁴²⁾ To persuade the promisee of his intention to perform, the promisor might bind himself to do so by undertaking to incur a cost on breach. For example, a medieval prince might seal his treaty by sending his son to live with his cocontractor. This would greatly increase the penalty for breach, and would permit the cocontractor to rely more on the prince's promise. Absent the bonding strategy, no one might rely on a promise, and the benefits of bargaining might be lost.

As in international law, legal sanctions in family law may inadequately constrain promise breakers. Divorce rights cannot be waived, with the result that the parties will walk into marriage with fewer expectations today than they had 100 years ago. Given the relaxation of legal enforcement, the parties might substitute bonding devices to signal their credibility. For example, the custom of giving a ring on an engagement can be seen as a bonding device, and ring-giving appears to have increased after the common law action for breach-of-promise was abolished.⁽⁴³⁾ Apart from a willingness to hazard material assets, a promisor might bind himself by undertaking to bear emotional distress on breach.⁽⁴⁴⁾ As A.E. Housman noted, giving one's heart away is a risky strategy.⁽⁴⁵⁾ However, the economist (if not the poet) might consider this a useful bonding device, if it reliably signals the promisor's credibility.

This assumes that the decision to bear emotional distress may be deliberate. The question how our reason might command our passions is an old one, much beloved of dualists, and a famous answer was given by Pascal. How is it, he asked, that one can come to believe in the Catholic faith, even if reason tells us that such a belief is reasonable? The knowledge that it is rational to believe does not produce belief, any more than the knowledge that it is rational to love produces love. Only custom and sentiment, and not rational argument, can persuade. Nevertheless, an internal reason can tell us how to harness external custom to effect a change in sentiments. "Il faut que l'extérieur soit joint à l'intérieur pour obtenir de Dieu; c'est-à-dire que l'on se mette à genoux, prie des lèvres, etc., afin que l'homme orgueilleux qui n'a voulu se soumettre à Dieu soit maintenant soumis à la créature."⁽⁴⁶⁾ So too, reason may tell a father to bond more closely with his children when the probability of a cut-off of custody rights is reduced. He might then spend more time with his children, knowing that this, like kneeling and praying aloud, will change his sentiments. Shaping one's passions in this way is not irrational, but is instead an example of how "[i]l n'y a rien de si conforme à la raison que ce désaveu de la raison."⁽⁴⁷⁾

Pascal's claim that reason may control the passions might offend the Romantic, who believes that one cannot choose to give one's heart away. But who of the two is right is an empirical objection, and the evidence more clearly supports Pascal than the Romantic. For example, the move to no-fault divorce laws plausibly increased the probability of divorce,⁽⁴⁸⁾ and is significantly correlated with lower marriage rates.⁽⁴⁹⁾ If we are a less romantic society today, then in part the blame may be laid at the door of divorce liberalization.

We therefore hypothesize that a move to joint custody will decrease divorce rates. Fathers will react to the change in the law by permitting themselves, through a thousand quotidian acts, to grow more attached to their families. And as a consequence, they will find themselves less ready to leave them.

Reducing divorce rates would almost certainly be in the best interests of children. Thirty years ago, before the run-up in divorce rates, liberationist philosophers, both male and female, argued that divorce did not harm children. Indeed, they argued, children might be better off after divorce if the parents have been fighting. But very few people, ideologues apart, still believe that increased divorce levels are benign. Children are surprisingly resilient in getting over parental fights.⁽⁵⁰⁾ What children do not get over is divorce.

A great deal of research suggests that divorce harms children.⁽⁵¹⁾ The least controversial way in which children are harmed is financially. Children of divorce make up a very large proportion of those below the poverty level ⁽⁵²⁾ and historically have received the majority share of public-assistance payments.⁽⁵³⁾ Even on conservative estimates, custodial parents (mostly women) and their children suffer a decline in living standards while noncustodial parents (mostly men) do better after divorce.⁽⁵⁴⁾ Quite apart from these wealth transfers, one would expect children to suffer financially on divorce. After separation, the parties must maintain two households, eliminating economies of scale that were present during the marriage.⁽⁵⁵⁾ Finally, decades of federal intervention have not ameliorated the child-support enforcement problem.⁽⁵⁶⁾ Nor can visitation rights be tied to child support.⁽⁵⁷⁾

Children also lose out through their distance from their parents. After separation, of course, the noncustodial parent will see far less of his children. What is not well realized is that this may be true of the custodial spouse as well, if she must find a job outside the home.⁽⁵⁸⁾ The custody arrangement simply cannot mirror the predivorce sharing of rewards and responsibilities.

Children of divorced parents lose more than financial resources.⁽⁵⁹⁾ Most no longer have two parents who are actively involved in raising them.⁽⁶⁰⁾ The children (particularly if young) may blame themselves for the divorce.⁽⁶¹⁾ If the parents continue to squabble over visitation and finances or who caused the marital dissolution, the children necessarily witness a pathological adult relationship. Even if the separation is peaceful, the custodial parent may be so overwhelmed by the heavy demands of full-time employment and single parenthood that there is simply little energy left for the children. Discipline may be neglected, and the children left largely to their own emotional and intellectual resources.⁽⁶²⁾ The picture becomes decidedly more complicated if either parent begins a new adult relationship: the children may feel (or even be) rejected for the new romance or a new half-sibling.

The costs of divorce for children have been studied in longitudinal comparisons between children of intact families and those of divorced parents. Short-term studies report that children are confused and depressed, sometimes clinically so.⁽⁶³⁾ They fare worse in school,⁽⁶⁴⁾ have problems in their peer relationships, and are more apt to "act out."⁽⁶⁵⁾ Over the longer term, researchers report that the children of divorce are more likely to drop out of school.⁽⁶⁶⁾ Girls, especially, are more likely to be promiscuous.⁽⁶⁷⁾ Boys are more likely to become delinquents or criminals.⁽⁶⁸⁾ Both sexes have a higher rate of marital failure when they grow up.⁽⁶⁹⁾

Joint custody might also result in better child rearing. If parents expect that divorce is possible, and that sole custody will be awarded to the parent to whom the child is closest, they have an incentive to cut out the other parent in a struggle for the child's affections, and turn the family into an Oedipal battlefield. Thus the move to joint custody might reduce parental possessiveness and self-centeredness in child rearing.⁽⁷⁰⁾

There would be a strong reason to promote joint custody if it significantly reduced divorce levels in the manner predicted by bonding theories. However, joint custody might actually result in increased divorce rates under incentive theories. To the extent that joint custody renders divorce less fearful, a spouse who would otherwise be noncustodial has more incentive to commit the matrimonial faults which lead to divorce. There is no reason a priori to believe that one theory better than another predicts divorce levels. They must therefore be tested empirically, as we do in Part IV.

B. Benefits After Divorce: Emotional and Financial Support

If children spend more time with their fathers under joint custody, this may benefit them in other ways. In general, two parents are better than one.⁽⁷¹⁾ Fathers will see their children as part of their normal life, and may dispense with the joyless search for "quality time" with them on weekends or vacations.⁽⁷²⁾ The parents will be better able to perform their complementary roles,⁽⁷³⁾ and to balance each other's power.⁽⁷⁴⁾ They may also more easily serve as exemplars whom the children may emulate as they mature.⁽⁷⁵⁾

Joint custody also formalizes a more normal bond between ex-spouses. The rancor of a divorce may be less bitterly felt and remembered when one knows that a common tie will remain and cannot be ignored. The joint deliberation over the child's future might also reduce the level of acrimony, even from the start.⁽⁷⁶⁾ This also will ease the pain of divorce for children.

We do not suggest that joint custody is a panacea. As we have noted, unfit parents should be denied joint custody. Joint custody may also require parents to cooperate with an ex-spouse to whom they feel bitter. As well, the custody arrangements will have to be redrawn when one parent decides to move away. However, we suggest that the promise of joint custody may reduce the number of unfit fathers under bonding theories. Family bonding before marriage may also reduce parental bickering and the probability of a move after a divorce.

C. Benefits After Divorce: Monitoring Theories

Even if joint custody does not affect physical custody, it might still serve as a useful monitoring device to reduce agency costs between the parties. Agency costs describe the costs of anticipated misbehavior by agents to their principals. As used by economists, the definition of principal and agent is broader than that used by lawyers. For economists, agency refers to any consensual relationship among two or more parties in which one, the principal, implicitly confers authority on the second, the agent, whose decisions may confer benefits or impose costs on the principal.⁽⁷⁷⁾

Agency-cost theories may easily be extended to family law.⁽⁷⁸⁾ The choice between joint ownership and community of property in marriage is in part a choice between two different responses to an agency-cost problem. Granting one spouse the right to bind the other on the sale of matrimonial assets may economize on the transaction costs of negotiating the sale, but the interspousal grant of authority will also impose agency costs: some spouses will improvidently agree to property transfers which the other spouse would wisely have vetoed.

Agency costs may also arise in child rearing, both in marriage and after divorce. In marriage, both parties will implicitly agree to a sharing or division of parental responsibilities. It is costly to require a parental conference before every minor child-rearing decision. Some decisions would never be made, and the child would learn to play one parent against the other. On more important decisions, however, the parents must balance these costs against the agency costs of unilateral decisions by one parent alone.

Divorce does not end, but instead exacerbates the agency-cost problem. Under sole custody, the noncustodial parent is asked to delegate exclusive child-rearing authority to the custodial parent at the same time that he is required to support the child. If the noncustodial parent has been found unfit to raise the child, this is just as it should be. But if the custody award is not an adverse comment on parenting abilities, the agency-cost problem is more pressing.

The noncustodial parent may be seen as a principal, and the custodial parent as an agent. The noncustodial parent will make child-support payments, but will not easily be able to monitor how the money is spent. He might simply disagree with the custodial parent's child-rearing decisions. Alternatively, he might worry that the custodial parent will shirk her duties or--worse still--misappropriate the funds.⁽⁷⁹⁾ The noncustodial parent would want to condition support payments on child expenditures.⁽⁸⁰⁾ But because he cannot verify actual expenditures on the child, this will prove unworkable.⁽⁸¹⁾ The noncustodial parent may react to the monitoring problem by cutting his support payments, to the child's detriment.⁽⁸²⁾

In other contexts, such as corporate law, the agency-cost problem may be more easily addressed through governance and liability strategies. For example, the misbehaving manager might have to account to a board of monitoring directors, or might be held liable civilly. However, these strategies are ordinarily not apposite in the family-law context.⁽⁸³⁾ Absent egregious misbehavior, civil liability for misbehavior by either party would be apt to hurt the child. For example, cutting off visitation rights to a parent who missed support payments might deprive the child of the benefits of contact with the absent parent. Similarly, the noncustodial parent cannot prevent the custodial parent from spending money for her personal benefit.⁽⁸⁴⁾ Moreover, if courts intervened over minor breaches, the parties might use the threat of litigation strategically. The atmosphere would be poisoned, and the benefits of joint deliberation over their child would be lost.⁽⁸⁵⁾

It is a mistake to assume that the interests of the child and the custodial parent must perfectly correspond. After an acrimonious divorce, the custodial parent may want emotional distance from the noncustodial parent, and may even want to hurt him.⁽⁸⁶⁾ "However much parents may love and care for their children, . . . their own quite valid interests in distancing themselves from former spouses may conflict with a child's interests in sustaining relationships with both parents or other loved ones."⁽⁸⁷⁾ This in turn may lead to a request for lower child support to minimize interference with the divorced family. If there is less visitation by a fit parent, both the noncustodial parent and the child lose.⁽⁸⁸⁾ The custodial parent may even reduce demands for financial support in exchange for reduced visitation time from her ex-spouse.⁽⁸⁹⁾

In a bitter divorce, the custodial parent might seek to turn the children against the noncustodial parent, and this may impose financial as well as emotional costs on them. The child who rejects the noncustodial parent is less likely to receive his financial support, and courts might even agree to relax support duties in such cases.⁽⁹⁰⁾

We suggest that joint-custody awards might usefully address these agency-cost concerns. More frequent and prolonged contact with the children allows parents to participate in day-to-day decisions involving the children's welfare.⁽⁹¹⁾ Thus joint custody facilitates monitoring strategies which permit both parents to oversee the child-rearing decisions the other makes. With joint custody, therefore, we would expect child-support payments to be given more readily. In the next Part we report on an empirical test which supports the monitoring hypothesis. These results are consistent with an earlier finding by Maccoby and Mnookin that joint-custody awards are positively and significantly correlated with increased child-support payments.⁽⁹²⁾

IV. An Empirical Test

This Part discusses the results of empirical tests of the bonding and monitoring hypotheses described in the previous Part. We first examined the determinants of divorce levels, and then the determinants of child-support ratios, using state-level data from 1980 through 1991. A joint-custody variable is a significant and negative predictor of divorce and a significant and positive predictor of support payments. These findings are consistent with the bonding and monitoring theories we describe above.

A. Bonding and Divorce

This Part describes a test of bonding explanations of joint custody. Our dependent variable DIVORCE is the per capita state divorce rate. To examine the effect of state joint-custody laws on DIVORCE levels in State i, we estimated the following reduced-form equation:

ln DIVORCE_it = ₀ + ₁ JOINT_it-1 + ₂ ln UNEMPLOYMENT_it-1 + ₃ ln METRO_it-1 + ₄ ln WORKING WOMEN_it-1 + ₅ ln ENTRY_i + ₆ ln YEAR + e_i

where the variables are defined as provided in Table II, and where

ln = natural logarithm

_{0 . . . 6} = regression coefficients

e = residual

i = 1, 2, . . . , 47 index for U.S. states

t = 1, 2, . . . , 12 index for years from 1980-91.

Divorce levels from 1980 through 1991 were regressed on 1979 through 1990 independent variables. Summary statistics are given in Table III. Unless otherwise mentioned, the source for our data is the Statistical Abstract of the United States.

All nondummy variables were transformed into their natural logarithmic form, after we determined that this was appropriate through a Box-Cox test on untransformed variables.⁽⁹³⁾

TABLE II. Definition of Variables

SOURCES: Source for JOINT: various state statutes, cross-checked with Marriage and Divorce in the United States, published in the winter issue of the Family Law Quarterly, various years. Source for JOINTCASE: National Center for Disease Control, National Center for Health Statistics, data for 1990 and 1991; more recent data obtained from phone calls to various state agencies. Source for WORKING WOMEN: Department of Labor, Bureau of Labor Statistics, printouts for various years. Source for all other data: Statistical Abstract of the United States (various years).

Table III. Summary Statistics

1. Dependent Variable

Our dependent variable, DIVORCE, represents total state divorces per year divided by state population. This is not the only way to measure divorce levels. Divorces might also be computed per married couple. Per capita divorce rates may be low because marriage rates are low, and not because married people are more faithful or happier in that state. The divorce rate will be zero in a state where no one marries. As a result, we re-estimated divorce levels on a per-married-couple basis. Because these results were very similar to the per capita figures, however, we omit them.⁽⁹⁴⁾

Divorce rates are far higher in Nevada than in other states.⁽⁹⁵⁾ We therefore excluded Nevada observations from our study. We were left with forty-seven continental U.S. states, over a twelve-year period, for a total of 564 observations.

2. Independent Variables

Our JOINT predictor is a dummy variable which takes the value of one if the state promotes joint custody on divorce, and zero otherwise. Because we expected lower divorce levels in joint-custody states, our model predicted that the JOINT coefficients would be negative. States were given the value of one whenever their statutes mentioned joint custody as a preference or an alternative, or when language in the statute encouraged each parent to spend significant time with the child. Where the statutory language was ambiguous, or where courts treated it as such, we looked to court decisions in categorizing the states.

The JOINT variable should be seen as a proxy for the actual custody dispositions made at divorce. Ultimately, what counts is the way courts decide custody in a state, and not the statutory regime. For example, a judge in a state which promotes joint custody might decide to award it in only the narrowest of circumstances. Our JOINT variable might thus be prone to Type I errors (with courts frowning on joint custody in the face of a statutory presumption) and Type II errors (with courts promoting joint custody without statutory encouragement).⁽⁹⁶⁾

Because of this, we sought to find out to what extent courts actually awarded joint custody. While such data is hard to come by, we were able to determine the percent of joint-custody awards for nineteen states for various recent years, for a total of sixty-nine observations.⁽⁹⁷⁾ This variable, JOINTCASE, we employed in Table VI to estimate divorce levels.

UNEMPLOYMENT, the yearly average of monthly unemployment rates,⁽⁹⁸⁾ is our proxy for economic conditions. We would expect to find higher divorce rates after economic downturns,⁽⁹⁹⁾ as economic hardship imposes strains on marriages. A spouse might have to work harder, spending more time away from his family, possibly even migrating to another state. In addition, where the parties have seen their wealth disappear in a severe economic downturn, the financial costs of a divorce might seem less troubling.⁽¹⁰⁰⁾ If one has lost nearly everything, there comes a point when there is less need to preserve what one has by staying married.

To reflect differences in social norms, we employed three social predictors: METRO, WORKING WOMEN, and ENTRY. Many more people divorce today than during the Great Depression. Divorce rates would therefore appear more sensitive to social norms than to economic factors. Increased divorce rates over the last thirty years may thus reflect a decline in social stigma, which reduced the cost of what used to be seen as deviant behavior.⁽¹⁰¹⁾