Chang and Sun (2009) investigate whether SOX can improve the quality of earnings
and strengthen corporate governance via the disclosure of audit committee independence,
by comparing the differences between earnings informativeness and corporate governance
between pre-SOX and post-SOX periods. First, they find that earnings informativeness
and decrease of earnings management is significantly associated with the audit committee
independence in post-SOX period, but not pre-SOX. Second, in both pre-SOX and
post-SOX periods, earnings informativeness is positively and significantly related to board
independence. Chang and Sun (2009) is the first study that tests the influence of SOX on
cross-listed foreign companies’ earnings quality, finding that SOX is efficient in
monitoring earnings quality.