Competition between companies is too fierce for self-regulation to work.公司间的竞争过于激烈，自我调节机制已无法发挥作用。They favour the self-regulation of the industry, and strict codes of conduct have already been issued by the Advertising Association.他们倾向于行业的自我监管，而广告联合会已经颁布了严格的行为规范。