| Variable | proxy variable | symbol | calculation method |
| Explained variable | Bank credit dupply for small and medium-sized enterprises |
| Log growth rate of corporate bank loans |
| Bank loan interest rate for small and medium-sized enterprises | RL | Ratio of current loan interest expenditure to total loan amount | |
| Explanatory variable | Quantitative monetary policy | QMP | obtained by weighted calculation according to the deposit reserve ratio and the proportion of deposit balance in total deposits of large financial institutions and small and medium-sized financial institutions |
| Price based monetary policy | PMP | calculated by time weighting according to the 7-day interbank offered rate | |
| Digital transformation index of commercial banks | DLL | calculated according to the digital transformation index of commercial banks of Peking University and the loan balance of local commercial banks | |
| Bank risk taking | Risk | Bank non-performing loan ratio | |
| Variable of control | Enterprise size | SIZE | Logarithm of total assets at the beginning of the period |
| Corporate age | AGE | Take the logarithm after subtracting the year of establishment of the enterprise from the sample year | |
| Return on net assets | ROE | Ratio of net profit to net assets | |
| Operating cash flow | CF | Ratio of net cash flow from operating activities of the enterprise in the current year to total assets at the beginning of the period | |
| Enterprise asset liability ratio | Lever | Ratio of total liabilities to total assets | |
| Composition rate of current assets of enterprises | LIQ | Ratio of current assets to total assets of enterprises | |
| Enterprise equity concentration | CRIO | Shareholding ratio of the top ten shareholders of the enterprise | |
| Regional economic development level | GDP | Nominal GDP growth rate | |
| Regional inflation | INF | Growth rate of consumer prices around the country |