3.1.2. Performance variables
We use Compustat and Center for Research in Security Prices (CRSP) data for our performance variables. We use the annual
accounting data from Compustat for calculating return-on-assets (“ROA”) and Tobin's Q. Following Barber and Lyon (1996), we
calculate ROA as operating income before depreciation divided by total assets. For robustness, we also consider operating income