Editing Common law (section)

=== Overruling precedent—the limits of ''stare decisis'' ===
The [[#United States federal system (1789 and 1938)|United States federal courts]] are divided into twelve regional circuits, each with a [[United States courts of appeals|circuit court of appeals]] (plus a thirteenth, the [[Court of Appeals for the Federal Circuit]], which hears appeals in patent cases and cases against the federal government, without geographic limitation). Decisions of one circuit court are binding on the district courts within the circuit and on the circuit court itself, but are only persuasive authority on sister circuits. District court decisions are not binding precedent at all, only persuasive.

Most of the U.S. federal courts of appeal have adopted a rule under which, in the event of any conflict in decisions of panels (most of the courts of appeal almost always sit in panels of three), the earlier panel decision is controlling, and a panel decision may only be overruled by the court of appeals sitting ''en banc'' (that is, all active judges of the court) or by a higher court.<ref>E.g., ''South Corp. v. United States'', 690 F.2d 1368 (Fed. Cir. 1982) (''en banc'' in relevant part) (explaining order of precedent binding on the United States Court of Appeals for the Federal Circuit); ''Bonner v. City of Prichard, Alabama'', 661 F.2d 1206 (11th Cir. 1981) (''en banc'') (after the Eleventh Circuit was split off from the Fifth Circuit, adopting precedent of Fifth Circuit as binding until overruled by the Eleventh Circuit ''en banc'': "The [pre-split] Fifth followed the absolute rule that a prior decision of the circuit (panel or ''en banc'') could not be overruled by a panel but only by the court sitting ''en banc''. The Eleventh Circuit decides in this case that it chooses, and will follow, this rule."); ''Ex parte Holt'', 19 USPQ2d 1211, 1214 (Bd. Patent App. & Interf. 1991) (explaining the hierarchy of precedent binding on tribunals of the United States Patent Office).</ref> In these courts, the older decision remains controlling when an issue comes up the third time.

Other courts, for example, the [[Court of Appeals for the Federal Circuit]] (formerly known as Court of Customs and Patent Appeals) and the [[SCOTUS|US Supreme Court]], always sit ''en banc'', and thus the ''later'' decision controls. These courts essentially overrule all previous cases in each new case, and older cases survive only to the extent they do not conflict with newer cases. The interpretations of these courts—for example, Supreme Court interpretations of the constitution or federal statutes—are stable only so long as the older interpretation maintains the support of a majority of the court. Older decisions persist through some combination of belief that the old decision is right, and that it is not sufficiently wrong to be overruled.

In the jurisdictions of [[England and Wales]] and of [[Northern Ireland]], since 2009, the [[Supreme Court of the United Kingdom]] has the authority to overrule and unify criminal law decisions of lower courts; it is the final court of appeal for civil law cases in all three of the UK jurisdictions, but not for criminal law cases in Scotland, where the [[High Court of Justiciary]] has this power instead (except on questions of law relating to reserved matters such as devolution and human rights). From 1966 to 2009, this power lay with the [[Judicial functions of the House of Lords|House of Lords]], as it declared in the [[Practice Statement]] of 1966.<ref>83 Cr App R 191, 73 Cr App R 266</ref>

Canada's federal system, described [[#CL Canada federal|below]], avoids regional variability of federal law by giving national jurisdiction to both layers of appellate courts.