| Variant nature | Variant name | Variant explanation |
| Explained variant | logAF | Logarithm of audit fee |
| Explaining variants | SBD | Scale of board of director |
| ID | Scale of independent directors | |
| IDP | Ratio of independent directors | |
| SR | Separation of two rights | |
| CR | Concentration of ownership | |
| DS | Consolidation of two rights or not | |
| SSH | Shareholding ratio of senior executive | |
| MSH | Shareholding ratio of board of directors | |
| DCSH | Nature of direct controlling shareholders and ratio of controlling share ratio | |
| Control variant | Lnsize | Scale of audited company |
| IR | Ratio of stock in total asset | |
| RR | Ratio of accounts receivable in total asset | |
| Lev | Asset-liability ratio | |
| NPL | Non-recurring loss and profit |