| Test type | Private R&D investment | New product sales | Number of patents |
| Single threshold test | 17.251*** | 9.262** | 7.732** |
| (0.000) | (0.013) | (0.043) | |
| Double threshold test | 15.471*** | 20.861*** | 19.562*** |
| (0.000) | (0.003) | (0.001) | |
| Triple threshold test | 4.821 | 3.151 | 1.791 |
| (0.897) | (0.578) | (0.734) | |
| Bootstrap times | 500 | 500 | 500 |