Preponderance of the evidence is the lowest of the three principal standards of proof in common-law systems, sitting below clear and convincing evidence and well below beyond a reasonable doubt. To meet it, the party bearing the burden of persuasion must show that their version of the facts is more probably true than not true. Courts commonly describe this as tipping the scales, however slightly, in one direction.
The standard governs most civil cases in the United States and other common-law jurisdictions, including contract disputes, torts, and many administrative proceedings. It is also the default standard in much of international arbitration and in fact-finding before bodies such as WTO panels and investor-state tribunals, though those forums often use the functionally similar phrasing "balance of probabilities" inherited from English law.
Several features distinguish it:
- Symmetry of risk. Because the threshold is just over 50%, the standard implicitly accepts a roughly equal risk of error on either side—appropriate where private parties are disputing money or property rather than liberty.
- Not a counting exercise. Quantity of witnesses or documents does not determine preponderance; the trier of fact weighs credibility and probative value.
- Distinct from prima facie proof. A prima facie case merely shifts the burden of production; preponderance is the ultimate persuasion standard at the close of evidence.
The U.S. Supreme Court reaffirmed the civil default in Grogan v. Garner, 498 U.S. 279 (1991), holding that preponderance applies unless a statute or constitutional concern demands more. Heightened standards apply, for example, to fraud claims, termination of parental rights (Santosky v. Kramer, 455 U.S. 745 (1982), requiring clear and convincing evidence), and deportation proceedings.
For MUN delegates and policy researchers, the standard often appears in debates over Title IX campus adjudications, sanctions compliance findings, and fact-finding mandates of UN commissions of inquiry, where the choice of evidentiary threshold shapes both legitimacy and outcomes.
Example
In *Grogan v. Garner* (1991), the U.S. Supreme Court held that creditors objecting to discharge of a debt in bankruptcy on fraud grounds need only prove their case by a preponderance of the evidence, not by clear and convincing evidence.
Frequently asked questions
Beyond a reasonable doubt is the criminal standard requiring near-certainty, while preponderance only requires that a fact be more likely true than not—roughly a >50% threshold.
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