| Variable category | Variable name | Variable symbol | Variable definitions |
| Explained variables | Tobin’s Q | q | Market price of the enterprise/replacement cost of the enterprise |
| Explanatory variables | Meeting attendance | att | Proportion of attending meetings in person |
| Objection | dlop | “Reserved opinion”, “Opposing opinion”, “No opinion”, “Abstention”, “Objection” and “Other” opinions are assigned the value of 1, otherwise 0 | |
| Resignation | res | Resignation of independent directors is assigned to 1, otherwise 0 | |
| Regulated variables | Independent Director Human Capital | idh | Std (Independent director title or working experience) + std (Average education of independent directors) + std (Average tenure of independent directors) |
| Control variables | Asset liability ratio | lev | Total liabilities/total assets |
| Proportion of state-owned shares | sta | State-owned equity/total equity | |
| Management capacity | tat | Total asset turnover | |
| ratio of independent directors | idr | Total number of independent directors/directors | |
| Company Size | size | The natural log of total assets over 10,000 | |
| ownership concentration | Top1 | Equity ratio of the largest shareholder | |
| Board size | boa | The natural log of the total number of directors | |
| The joining together of two job | dual | The general manager and the chairman of the board are equal to 0, otherwise 1 | |
| Off-site director | idd | If the board of directors contains remote directors, it is 1, otherwise it is 0 |