While competing policies favor or disfavor aggregration of related cases, the procedural device is perceived efficient and it is here to stay. Aggregate proceedings might involve few parties or, as in cases involving product defects, securities fraud, or mass disaster, might bring under the same litigation umbrella many thousands of plaintiffs and multiple defendants. This volume aims to help lawyers, judges, legislators, and others make the correct decision regarding aggregation. It also aims to improve the management of cases in which aggregation is allowed.