All variables are deflated by average total assets in order to avoid problems
of heteroscedacity. Average total assets are calculated for firm i in year t as the
mean of the firm’s total assets in years t– 1 and t. The model is estimated in its
cross-sectional version for each industry–year combination, based on the industry
classification of the Madrid Stock Exchange. The residual vector reflects the
variation in working capital accruals unexplained by cash flows of the previous,
current and subsequent periods. Therefore, the absolute value of the residual for
each firm-year observation is an inverse measure of accruals quality
(AQ_DDit) = | eit
| (the higher the residual, the lower the accruals quality).