As the primary test of our predictions, we compare accounting quality metrics for IAS firms and NIAS firms in the period after the LAS firms adopt IAS, that is, the post adoption period. This permits us to determine whe dier firms that apply IAS have higher accounting quality than firms that do not.
One potential problem with comparing IAS and NIAS firms in the post adoption period is that the two groups of firms could exhibit differences in accounting quality in the post adoption period because their economic char-acteristics differ. To determine whether this is tire case, we compare IAS and NLAS firms’ accounting quality before the IAS firms adopt IAS, that is, the pre adoption period. Finding IAS and NIAS firms exhibit similar differences in accounting quality in the pre- and post adoption periods would make it difficult to attribute post adoption differences in accounting quality to the change in financial reporting for IAS firms. Conversely, finding that accounting quality for IAS and NIAS firms is similar in the pre adoption period but is different in the post adoption period would make it less likely that differences in accounting quality in the post adoption period are attributable to differences in economic characteristics between the two groups of firms.