Arbitral awards are intended to be binding on parties who subject their disputes to arbitration. However, an arbitrator’s bias in favor of one of the parties is one of the few grounds on which a party can object to such an award. The standard used to evaluate such bias is known as “evident
partiality.”

This Note examines two commonly used standards—referred to in this Note as the “possible impression” standard and the “likely actual bias” standard—deployed by U.S. courts to define evident partiality and determine whether the requirements for vacating an arbitral award have been fulfilled. This Note advocates that likely actual bias is the correct standard by which courts should determine whether an arbitral award should be vacated for evident partiality ex post—that is, after arbitration. This Note further advocates for a private law solution, which would apply the less demanding possible impression standard to arbitrators’ required disclosures ex ante—before arbitration—and impose an affirmative duty on parties to investigate arbitrators’ potential biases.