Three techniques are used to assess comparability: ‘The first is the similarity of accounting
functions measure … With this approach, … information comparability can be defined
as the similarity of firms’ accounting functions that translate economic transactions into
accounting data.’ This method correlates accounting data, the return on assets, with stock
market returns. ‘The second proxy is the degree of information transfer, as measured by the
association between the earnings surprise of an announcing firm and the contemporaneous
stock price movements of other firms… The third proxy is the similarity of the information
content of earnings … and the information content of the book value of equity …, as
measured by the long-window association between stock price and earnings and the book
price of equity.