What significance did U.S. vs. South-Eastern Underwriters have on the insurance industry?

U.S. vs. South-Eastern Underwriters was a landmark antitrust case, decided by the Supreme Court in 1944. The Court held that the South-Eastern Underwriters Association, an inter-insurance exchange amongst a group of Southern insurance companies, was in violation of the Sherman Antitrust Act and constituted a monopoly. This decision overturned the lower court's ruling that, because the association was a voluntary trade organization that merely provided advisory services to its members, rather than directly offering collective services, it did not constitute a monopoly. The Supreme Court's ruling that collective action among companies, even without selling services jointly, was a form of monopoly set an important precedent in antitrust law, and had a major effect on the insurance industry. The Court's decision opened up the insurance industry to more competition, increasing the number of companies and rates available, making it easier for consumers to find the policy that was right for them. This case also established an important legal precedence that other industries have used to pursue antitrust cases against companies and organizations engaging in concerted actions.