In a second set of tests (for which the sample is not broken down by country), the authors
look at changes in the comparability of publicly-traded and private firms from the same
country. They find that, ‘post IFRS adoption, the accounting information of public firms
adopting IFRS becomes less comparable to the information provided by local GAAP private
firms from the same country’. However, in these tests, the authors also ‘find a positive
average comparability effect of mandatory IFRS adoption for European firms when we use
private firms from the same country as a control group.’