Old men. That’s who decide most investor disputes in the United States, according to a study by the Public Investors Arbitration Bar Association, which found that 80 percent of arbitrators associated with the Financial Industry Regulatory Authority Inc. are men, with an average age of 69.

The bar association analyzed a pool of 5,375 FINRA arbitrators charged with deciding disputes between investors and brokers or brokerage firms, and sharply criticized the self-regulatory organization for its lack of diversity and transparency.