5.1. The Consideration of Industrial and Yearly Effects
We add two types of dummy variables in the QR. One is the industrial
dummy, which is used to control the variation of stock-based compensation
in different industries. The other is the year dummy, which is
used to capture different economic conditions in different years. We
construct the industrial dummies by using one-digit SIC code, which
can alleviate the complexity of estimation in QR.8 Consequently, there
are nine industrial dummies and 13 year dummies in the empirical
model. The estimation results are summarized in Table 5.