| Variable | Obs | Mean | Std. Dev. | Min | Max |
| y | 530 | 0.418 | 0.218 | 0.109 | 1.266 |
| x | 530 | 9.799 | 2.271 | 3.569 | 13.767 |
| x1 | 530 | 102.329 | 65.289 | 24.052 | 360.07 |
| x2 | 530 | 62.339 | 16.424 | 19.753 | 86.925 |
| x3 | 530 | 1.852 | 3.335 | −10.016 | 8.824 |
| x4 | 530 | 8.843 | 2.329 | 1.981 | 12.99 |