In the United States, federal and most state courts allow class action suits. Such suits have figured prominently in civil-rights litigation and in other cases brought to further social and economic reform. In recent decades they have been employed notably by groups of consumers and others seeking to affix liability for harm caused by various products, especially through manufacturers' negligence. Major litigation against the producers of the Dalkon shield (an intrauterine device; see birth control), of Agent Orange (a herbicide used as a defoliant in the Vietnam War), and of asbestos insulation has involved class action suits.
Since the 1980s such suits have been under attack, along with negligence litigation in general, with opponents, mainly conservatives and business interests, arguing that many lawsuits are frivolous and that awards are out of proportion to the offense in some juridictions. A study published in 2004 that reviewed several hundred state and federal class action lawsuits from 1993 to 2002 found that, adjusted for inflation, the average annual award in such suits varied but did not progressively increase, while the median award was relatively constant. At the same time, however, federal court data showed that the number of class action lawsuits doubled from 1997 to 2002.
See study by S. Yeazell (1987).