Table 1 The classification of control variables

1. Tradable shares (TSHARE),

2. The sum of the square of the top five shareholders' shareholdings (SHRHFD5)

3. Free float (FREE)

4. Stock return (RET)

5. Stock turnover (TO)

6. Return volatility (VOL)

7. Earnings (EARN)

8. Intangibles (INTAN)

9. Leverage (LEV)

10. Return on equity (ROE)

11. Tobin’s Q (Q)

12. Book to market (BTM)

13. Capital expenditures (CAPITAL)

14. Sales growth (SALES)

15. Firm age (AGE)