Is CEO certification of earnings numbers value-relevant?

On June 27, 2002, the Securities and Exchange Commission of the United States ordered the CEOs and CFOs of 688 large firms to certify the earnings numbers of their companies by 5:30PM EST, Aug 14, 2002. This paper uses this natural experiment to find that certification was not only a non-event for the certifiers around their certification date, but it was also a non-event for the non-certifiers around Aug 15, 2002. Further tests make us conclude that CEO certification of earnings numbers is not value-relevant.