dissenting.
The Hague Convention on the Civil Aspects of International Child Abduction1 (“Hague Convention”) exists to ensure the prompt return of children wrongfully retained to the state of the child’s habitual residence. Hague Convention, Preamble. According to the Convention, a retention is “wrongful” where:
a) it is in breach of rights of custody attributed to a person, an institution or any other body, either jointly or alone, under the law of the State in which the child was habitually resident immediately before the removal or retention; and b) at the time of removal or retention those rights were actually exercised, either jointly or alone, or would have been so exercised but for the removal or retention.
Id., Article 3. Although the word “retention” itself is not defined, the Hague Convention does define “rights of custody,” and contrasts it with the mere “rights of access” for which the Hague Convention does not provide the remedy of the child’s return:
a) “rights of custody” shall include rights relating to the care of the person of the child and, in particular, the right to determine the child’s place of residence;
*559b) “rights of access” shall include the right to take a child for a limited period of time to a place other than the child’s habitual residence.
Id., Article 5.
The district court looked to the Third Circuit’s decision in Karkkainen v. Kovalchuk, 445 F.3d 280, 287 (3d Cir.2006), for the following process in Hague Convention cases:
(1) When did the removal or retention at issue take place?
(2) Immediately prior to the removal or retention, in which state was the child habitually resident? (3) Did the removal or retention breach the rights of custody attributed to the petitioner under the law of the habitual residence? (4) Was the petitioner exercising those rights at the time of the removal or retention?
Id. at 287. Using this formula, the district court concluded that the United States was the child’s habitual residence, and so it denied Hofít’s petition for return of the child to Israel.
The majority denies Hofit’s petition on appeal, but it relies primarily on a different reason. According to the court, the retention was not wrongful in this case because Avraham “did not commit a ‘breach of rights of custody ... under the law of the State in which the child was habitually resident immediately before the [alleged] removal or retention.’ ” Maj. Op. at 554 (quoting Hague Convention, Article 3). The majority also concludes in dicta that the district court did not commit procedural error by failing to give any consideration to Israel as Orin’s habitual residence. For the following reasons, I dissent.
I.
Neither in the district court, nor on appeal did Avraham argue that he did not breach Hofit’s right of custody. Even in denying Hofit’s petition, the district court concluded that Hofit, as Orin’s mother, had a “right of custody” under both Israeli and Ohio law. Yet the majority concludes that Avraham did not breach a right of custody of Hofit’s. I believe that is incorrect.
The Hague Convention defines a “right of custody” in particular to include “the right to determine the child’s place of residence.” Hague Convention, Article 5. The majority readily admits that under both Israeli and Ohio law, as Orin’s mother, Hofit had a right to determine the child’s place of residence. Maj. Op. at 558. At the time of the alleged retention, Hofit shared the joint right of custody with Avraham as Orin’s married parents. Id. The Perez-Vera Report2 also makes clear that the Hague Convention contemplates joint custody. “[T]he whole tenor of article 3[, which defines wrongful retention,] leaves no room for doubt that the Convention seeks to protect joint custody____” Perez-Vera Report ¶ 84. In other words, a right of custody that is joint and shared with another is a “right of custody” under the Hague Convention. Both parents have a “right of custody” under the Hague Convention.
*560That right is breached if another person, even if that person is the other joint holder of a right of custody, unilaterally determines the child’s place of residence. “[T]he removal [or retention] of a child by one of the joint holders [of custody] without the consent of the other ... has disregarded the rights of the other parent which are also protected by law ...” and so is wrongful. Perez-Vera Report ¶ 71. When Hofit wanted Orin to come with her to Israel and Avraham subsequently prevented Orin’s departure from Ohio, Avraham unilaterally decided Orin’s place of residence. By taking such “unilateral action,” Avraham breached Hofit’s right of custody.3 See id.
II.
Although the majority disposes of the case on “right of custody” grounds, the district court focused on the “habitual residence” analysis and denied Hofit’s claim on this issue. In my opinion, the district court was right to focus on Orin’s habitual residence, but it committed reversible error by failing to compare his relationship to the United States with his relationship to Israel.
The Hague Convention is intended to prevent a child from being “taken out of the family and social environment in which its life has developed.” Perez-Vera Report ¶ 12. That results when a court refuses “to restore a child to its own environment after a stay abroad.” Id. The court in Robert v. Tesson, 507 F.3d 981 (6th Cir.2007), understood these dictates to mean that habitual residence must be determined by comparing the levels of attachment the child has to each of the states in which he or she has resided. 507 F.3d at 996-98. Just as Orin here, the children in Robert had lived in two countries, and the court compared the children’s relationships with the two places to determine which had a superior claim to being the children’s habitual residence. Cf. Friedrich v. Friedrich, 983 F.2d 1396, 1402 (6th Cir.1993) (only analyzing the child’s habitual residence with respect to Germany in the “simple case” where the child had resided exclusively in Germany prior to the removal).
The comparative essence of the habitual residence inquiry is captured in the object of the Hague Convention- — determining “which country is the proper forum for [the] custody determination,” Koch v. Koch, 450 F.3d 703, 711 (7th Cir.2006), not merely whether one forum suffices for the custody determination. This takes into account forum shopping, Robert, 507 F.3d at 988, which is not at issue in this case,4 and the best place for the child during the pendency of custody proceedings, not simply a place where it is satisfactory for the child to live. See id. (looking to “the family and social environment in which [the child’s] life has developed,” not merely an acceptable locale for the child to reside until custody is decided (quoting Perez-Vera Report ¶ 12)).
To perform this analysis properly, the court in Robert proceeded as follows: (1) the court recognized the habitual residence factors as they related to the United States, id. at 996-97; (2) the court held that the children’s habitual residence was *561the United States before they entered France, id. at 997; (3) the court analyzed the habitual residence factors with respect to France, id. at 997-98; and (4) the court decided that it could not conclude that “the [children’s] settled purpose [was] to leave the United States behind and make a new habitual residence in the United States,” and that the children’s habitual residence was thus the United States, id. at 998. Significantly, the court also made this conclusion even though the children had last lived in France prior to the removal. Id. at 997-98.
In the case at hand, the district court failed to make such a comparison; it gave no consideration at all to the alternative possibility of Israel as Orin’s habitual residence despite the myriad of evidence in the record that could have been used to do so. Orin was born and raised in Israel, having lived there until almost the age of three. From Israel, which was his only residence until that point, Orin moved to the United States with his parents on April 1, 2007. He had lived in the United States for only five-and-a-half months when his father and mother separated and his father prevented his mother from taking Orin with her when she returned to Israel. Throughout his stay, Orin had a close relationship with his extended family in Israel, especially his grandfather, id., and his cousins, id. at. 63. Orin also had a self-evidently close relationship with his mother,5 who also now resides in Israel. Yet, contrary to the Hague Convention and our case law interpreting it, the district court explicitly rejected any consideration of Israel as Orin’s habitual residence, writing:
Petitioner argues that Orin is acclimated to Israel and not the U.S. because, when in Israel, Orin was part of his mother’s large extended family in Tirat Karmel, had many friends in Tirat Karmel, spent most of his time with his mother, and was very close to his teacher. While this may be true, the Court must look to whether Orin has become acclimated to the U.S.
Id. at 70 (emphasis added). Nowhere else in the district court’s opinion does it allude to the possibility of Israel as Orin’s habitual residence. See id. at 66-72. The district court thus failed to give any consideration to Israel as Orin’s habitual residence that Robert requires.
Meanwhile, the comparative factors indicating the United States as Orin’s habitual residence are not particularly strong. The child’s age and the fact that he had to be taken to such places renders plausible the court’s reliance on some of the items that it identified as important, e.g., visiting parks, id. at 69, regular trips to the U.S. Air Force Museum, id., the possession of toys, id., and vague notions such as Orin’s “socializing] with [] children at Synagogue” and “parties and other social activities,” id. There is also a telling lack of testimony on these factors from any noninterested parties, such as teachers or administrators from Orin’s school in Ohio. Finally, the district court also failed to scrutinize Orin’s relationship with his father while they were in the United States. The court in Robert took the limited inter*562action between the children and their father while they resided in America, as well as the fact that the father “did little to welcome them” upon arriving in France, as evidence that the children’s habitual residence was the United States and not France. 507 F.3d at 997-98. Similarly here, Avraham was away on business for almost a month-and-a-half of the five-and-a-half months Orin resided in the United States, a point which the district court seemingly ignored. The weakness of the evidence in support the United States as Orin’s habitual residence lends credence to Hofit’s claim that Israel is Orin’s habitual residence. Although some evidence in the record supports, to some degree, the United States as Orin’s habitual residence, the evidence must be sufficient to establish a change in habitual residence, since it is uncontested that Israel was Orin’s habitual residence before the initial move to Ohio.
Put differently, sufficiency of acclimatization to a new place will vary based on the strength of a child’s relationship with his or her prior habitual residence. If Orin had little attachment to Israel, little would be needed to acclimatize him to the United States. But since he spoke Hebrew exclusively for the first three-and-a-half years of his life, had close ties to his mother who resides in Israel, and had close ties to his mother’s extended family who all reside in Israel, then much should be required to show acclimatization to a new place. Regardless, the district court never decided the critical issue because it committed significant procedural error. For that reason, I would reverse the judgment of the district court and remand to the district court to consider Orin’s relation to Israel in its determination of the child’s habitual residence as required by the Hague Convention.
. Although the title of the Hague Convention includes the word "abduction,” the drafters did so only because of the word’s "habitual use by the 'mass media’ and its resonance in the public mind.” Elisa Perez-Vera, Explanatory Report ¶ 53, in 3 Hague Conference on Private International Law, Acts and Documents of the Fourteenth Session, Child Abduction 1069 (1982) ("Perez-Vera Report”). Indeed, there exists a "lack of correspondence between the title of the Convention and the terms used in [its] text.” Id. The actual text of the Hague Convention refers to "removal” and "retention” and treats them symmetrically-
. “Many circuits hold Professor Elisa Perez-Vera's report to be an authoritative source for interpreting the [Hague] Convention’s provisions and indeed the Hague Convention itself recognized Perez-Vera's report as official commentary.” Robert v. Tesson, 507 F.3d 981, 988 n. 3 (6th Cir.2007) (internal citations omitted). "[Professor Perez-Vera’s] explanatory report is recognized by the Conference as the official history and commentary on the Convention and is a source of background on the meaning of the provisions of the Convention available to all States becoming parties to it.” Id. (quoting Hague International Child Abduction Convention; Text and Legal Analysis, 51 Fed.Reg. 10494, 10503 (1986)) (internal quotation marks omitted).
. On the other hand, if Hofit had taken Orin to Israel with her, against Avraham’s wishes, Hofit would have breached Avraham’s right of custody under the Hague Convention because they shared the right to determine Orin’s place of residence. But such a scenario is not at issue in this case.
. Contrary to the majority’s assertion, Maj. Op. at 557, forum shopping is not an issue at all in this case. Neither the district court, which denied the return of the child to Israel, nor Avraham argued that Hofit returned to Israel to seek a more favorable custody determination.
. The closeness of this relationship is evident even only looking at it in retrospect as the court in Robert required, and not prospectively as in a custody determination. The mother resided and now resides in Israel and therefore Orin has a (most) significant relationship with a person in Israel, just as he has a relationship with his cousins in Israel, which all militates in favor of a habitual residence in Israel. The district court’s complete lack of consideration of Orin’s relationship with his mother, however, represents significant error in and of itself. See, e.g., Pielage v. McConnell, 516 F.3d 1282, 1289 (11th Cir.2008) (a young child’s "family environment was with his mother”).