opinion: Per Curiam.
  This school desegregation case involves the School District of Omaha, Neb. The District Court in a comprehensive opinion extensively reviewed the evidence presented by the parties, and recognized that there was considerable racial imbalance in school attendance patterns. Applying a legal standard which placed the burden of proving intentional segre-gative actions on the respondents, and which regarded the natural and foreseeable consequences of petitioners' conduct as "neither determinative nor immaterial” but as “one additional factor to be weighed,” the District Court concluded that the respondent had not carried the burden of proving a deliberate policy of racial segregation. 389 F. Supp. 293. On appeal, the Court of Appeals rejected the legal standard applied by the District Court, 521 F. 2d 530, stating that’ a “presumption of segregative intent” arises from actions' or omissions whose natural and foreseeable result is to “bring about or maintain segregation.” Id., at 535. Reviewing the facts found by the District Court concerning faculty assignment, student transfers, optional attendance zones, school construction, and the deterioration of one high school in the district, the Court of Appeals generally accepted these factual findings. In each instance, however, it concluded that there was sufficient evidence under the legal standard it adopted to shift the burden of proof to the petitioners. Finding that in no instance had the petitioners carried their rebuttal burden, the Court of Appeals remanded for the formulation of a sys-temwide remedy. We denied certiorari. 423 U. S. 946.
  Following the explicit instruction of the Court of Appeals, the District Court promulgated an extensive plan involving, among other elements, the systemwide transportation of pupils. On petitioners’ appeal, the Court of Appeals for the Eighth Circuit affirmed. 541 F. 2d 708.
  In Washington v. Davis, 426 U. S. 229, 239 (1976), we said:
  “[0]ur cases have not embraced the proposition that a law or other official act, without regard to whether it reflects a racially discriminatory purpose, is unconstitutional solely because it has a racially disproportionate impact.”
  We restated and amplified the implications of this holding in Arlington Heights v. Metropolitan Housing Dev. Corp., 429 U. S. 252 (1977).
  Neither the Court of Appeals nor the District Court, in addressing itself to the remedial plan mandated by the earlier decision of the Court of Appeals, addressed itself to the inquiry required by our opinion in Dayton Board of Education v. Brinkman, ante, p. 406, in which we said:
  “If such violations are found, the District Court in the first instance, subject to review by the Court of Appeals, must determine how much incremental segregative effect these violations had on the racial distribution of the Dayton school population as presently constituted, when that distribution is compared to what it would have been in the absence of such constitutional violations. The remedy must be designed to redress that difference, and only if there has been a systemwide impact may there be a systemwide remedy.” Ante, at 420.
  The petition for certiorari is accordingly granted, the judgment of the Court of Appeals is vacated, and the case is remanded for reconsideration in the light of Arlington Heights and Dayton.
  It is so ordered.
choices: case did not arise on cert or cert not granted federal court conflict federal court conflict and to resolve important or significant question putative conflict conflict between federal court and state court state court conflict federal court confusion or uncertainty state court confusion or uncertainty federal court and state court confusion or uncertainty to resolve important or significant question to resolve question presented no reason given other reason