| Category | Variable name | Variable symbol | Variable description |
| Explained variable | Book leverage (asset-liability ratio) | bkl | Total debt/Total assets |
| Market value leverage | mkl | Total debt/Market price of equity | |
| Explanatory variable | Company size | size | Natural logarithm of total assets |
| Market-to-book ratio | mtbr_a | Market price of equity/Total assets | |
| Profitability | prof | EBITDA/Total assets | |
| Asset tangibility | tang | (Net value of fixed assets + Net value of stock)/Total assets | |
| Control variable | Altman Z Scoring Value | zscore | 1.2 * current capital/total assets + 1.4 * retained earnings/total assets + 3.3 * EBIT/total assets + 0.6 * market price of equity/total liabilities + sales revenue/total assets |
| Non-debt tax shield | shield | Depreciation of fixed assets/Total assets | |
| Selling, general and administrative costs | sgax | (Sales cost + management fees)/Total assets | |
| Capital investment | capin | Capital expenditure/(net value of fixed assets of the previous period+ net value of inventory of the previous period) | |
| Annual rate of return of individual share | stkrt |
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