| Variable Type | Variables | Variable Symbols | Variable Description |
| Explained variable | Total factor productivity | tfp | The natural logarithm is taken after calculated by LP |
| Explanatory variable | Outward foreign direct investment | ofdi | The year when OFDI exists assigned a value of 1, otherwise assigned a value of 0 |
| Mediating variables | Technological innovation | inn | ln (total amount of enterprise R&D investment + 1) |
| Exploratory Innovation | eri | ln (amount of expensed R&D investment (expenditure) + 1) | |
| Exploitative innovation | eti | ln (amount of capitalized R&D investment (expenditure) + 1) | |
| Control variables | Enterprise size | size | ln (net fixed assets + 1) |
| Company age | age | ln (current year - year of listing + 1) | |
| Debt to asset ratio | lev | Total liabilities/total assets | |
| Return on total assets | roa | Net profit/average total assets | |
| Growth rate of operating income | growth | Difference between the operating income of the current period and that of the previous year/operating income of previous period | |
| Export | export | ln (Enterprise overseas sales revenue + 1) | |
| Year | year | Dummy variable of year to control the impact of macro-environmental changes | |
| Enterprise | stkcd | Dummy variable of enterprise to control inter-enterprise effects |