1 In France in 2020, 480,000 children—12% of the children of separated parents [1]—split their time evenly between the homes of their two parents. The practice of alternating residence [2] is a growing phenomenon, but despite the law of 4 March 2002 on joint parental authority that legalized the practice (without proposing it by default [3]), it only represents a minority of cases and is less common than in some other countries. Benoît Hachet devoted his doctoral study in sociology, defended in 2018, to these separated parents whose children’s lives are divided equally (paritaire [4]) between their two parents’ homes. Some of the results are summarized in this book. It is based mainly on personal narratives, with some helpful quantitative results from a survey questionnaire answered by around 5,000 parents who receive aid for domestic expenses from a French national body known as the Caisse nationale des allocations familiales. [5]

2 There is as yet little research on alternating residence. Where it exists, it most often focuses the debate on studies in child development from a psychiatric perspective, the determinants of this type of residential arrangement, the legal process that leads to it, [6] and gender relations. One of the original aspects of Hachet’s book is his choice to examine alternating residence from the parents’ perspective. How does it reconfigure their daily lives? This choice can be understood in the light of the author’s own story, as he highlights: as a parent in this very situation himself, the research question arose naturally.

3 The first part of the book sets out the context of alternating residence arrangements. The source of various controversies, it is socially differentiated and more widespread in the middle and upper socio-economic strata. Most parents in this situation share childrearing duties before they separate. Couples sometimes plan for this possibility even before they have children, and it is often settled upon amicably, more rarely through the courts.

4 After an overview of the contexts and experiences of his participants (Part 2), Hachet takes us on a voyage in ‘space’, or rather the ‘spaces’ (in a broad sense) of these parents’ lives. First, there is the question of their own housing situation. Some continue to live under the same roof, often for economic reasons, but in most cases each has independent accommodation somewhere around the children’s school. Others attempt, for a time and not without difficulty, an ‘alternating nest’ arrangement (where the children live continuously in the same residence, and the parents take turns living with them every other week). He also looks at space from the broader perspective of geographic mobility—or rather immobility, with some parents refraining from moving for professional or romantic reasons because it would get in the way of this residential arrangement. Geographical proximity between parents is thus a condition for alternating residence. Finally, there is the question of the occupation of the interior space of each parent’s home. Due to housing costs, some use the living-room sofa as a bed, even when their children are absent, while the bedroom remains a reserved space, whose closed door or put-away toys act as a reminder of the children’s absence. Some even go elsewhere during some of their weeks without the children.

5 The fourth part of the book deals with the organization of time. Apart from the summer holidays, parental schedules are most often biweekly, with a transition close to or during the weekend: even-numbered weeks with the father, odd-numbered weeks with the mother. During their weeks with children, which parents sometimes cross-hatch in their diary for the entire year, they tend to be less active both professionally and personally, and vice versa. But other arrangements exist, including in particular cases with more frequent transitions when the children are very young. The day, time, and place of these transitions are not left to chance. Unforeseen events sometimes challenge these arrangements, as do situations where parents have to juggle between multiple situations of alternation, such as their own and that of a new partner.

6 In addition to the question of costs (mainly shared) and the children’s wardrobe (generally duplicated), the fifth part delves into parental practices. Parents sometimes overinvest in their weeks with children, hoping to compensate for time apart. When both partners were strongly involved in childrearing before separation, they remain so afterwards, while others previously less present, most often fathers, become more involved. Separation presents each parent with prospects of ‘parental sovereignty’ and their own ‘parenting styles’. ‘Each parent manages with their own rules on their parental territory, even if it displeases the other parent’ (p. 176). This means children are faced with different norms and practices, a source both of enrichment for the children and of frictions between parents.

7 Alternation also raises the question of ‘parental continuity beyond the phase when the children are present’ (p. 184). Some (around two-fifths) consider that they switch from being parents during their weeks with children to being a man or woman during the weeks without them. The latter creates spaces for other activities and forms of social relations, including the romantic or intimate. The majority compartmentalize the two spheres, avoiding bringing a new partner home when the children are there, at least in the early stages of the separation. They generally describe the experience of their weeks without children in positive terms, although this is less true shortly after separation, when the children are small, and in case of parental conflicts. ‘Alternation creates temporal spaces of freedom…. Each parent makes something of these new moments, which prove to be more novel for women than for men, as they were more often responsible for children’s affairs’ (p. 195). Hachet also looks at table practices, which differ depending on whether the children are present.

8 The book ends on the thorny question of repartnering. Separated parents form new unions, with others who may also already have children and with whom they may or may not cohabit. Sometimes these couples look to have other children. Separated parents may find themselves spending more time with the children of their new partner than with their own, an imbalance that can generate frustration.

9 Thanks to the originality of Hachet’s approach (focus on the parents’ point of view, cases of equally divided alternating residence, and the study of spaces and temporalities) and the complementarity of his methods, this book undeniably provides new and valuable knowledge, both on family relations and on parental practices. It also inspires curiosity and invites further research. For example, what are the specificities of evenly split 50–50 residence arrangements compared to less equal situations (40–60 or 30–70)? And the clearly rich quantitative survey calls for deeper exploration.

10 With its division into small sections, a clear, flowing style, and the choice not to clutter the text with references or statistical tables, this book is accessible and a pleasant read. This editorial choice may have two drawbacks. First, it leaves Hachet little space to precisely characterize the situations he describes (despite the appendix presenting each parent) and thus to link the stories of alternating residence to these lives more broadly. Secondly, the use of a first-person voice and the evocation of the author’s own experiences, and those of his friends and family, give the study a novelistic tint. This probably casts alternating residence in slightly too enchanted a light. This type of arrangement is certainly more common in cases of peaceful separation, but it can also be the focus of intense conflict, something nonetheless apparent in a few passages. While some parents may have a friendly drink together during moments of transition, others carefully avoid each other, even going so far as to leave the children’s belongings in the lobby of the other parent’s building. But Hachet may have failed to pick up some of these more ‘difficult’ situations, either because they transformed into something else (thus leaving the field of the study), or because the parents were less willing to share their experience with him as a researcher.