Sample and data
We base our tests on a sample of firms that adopted IFRS between 1995 and 2006. Pre-adoption sample years
potentially range from 1992 through 2005. Post-adoption sample years potentially range from 1996 through 2009. We
obtain our sample of IFRS firms from Worldscope, which identifies the set of accounting standards a firm uses to prepare
its financial statements and its industry. The Worldscope standards categories that we code as IFRS based on the
Worldscope Accounting Standards Applied data field are ‘‘international standards’’ and ‘‘IASC’’ or ‘‘IFRS.’’
There are two
sources of potential error in classifying a firm as applying IFRS. The first is that firms do not always indicate clearly the
accounting standards that they apply. The second is that Daske et al. (2007) reports that the Worldscope data field contains
classification errors. If a substantial portion of firms we classify as IFRS firms is affected by these sources of classification
error and if IFRS-based accounting amounts are more comparable to US GAAP-based accounting amounts than are
accounting amounts based on other standards, it is likely that our tests are biased against our finding that IFRS- and US
GAAP-based accounting amounts are comparable.
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We limit IFRS firms to those that do not cross-list in the US to
eliminate effects on the IFRS accounting amounts associated with the reconciliation requirement (Harris and Muller, 1999;
Lang et al., 2006).