The objective of this study is to determine the extent to which application of International Financial Reporting
Standards (IFRS) by non-US firms (hereafter, IFRS firms) results in accounting amounts that are comparable to those
resulting from application of US Generally Accepted Accounting Principles (GAAP) by US firms. We make this
determination by addressing two questions. The first is whether comparability is greater after firms apply IFRS than
when they applied non-US domestic standards. The second is whether comparability differs after firms adopt IFRS
depending on whether a firm mandatorily adopts IFRS, depending on the legal origin and extent of enforcement of an IFRS
firm’s country, and in more recent reporting years. Although there is a growing literature examining whether application
of IFRS affects the quality of accounting amounts and has economic implications in capital markets (see Hail et al., 2010a,
2010b), no study directly examines the extent to which application of IFRS by IFRS firms results in accounting amounts
that are comparable to those based on application of US GAAP by US firms.