eger</td> <td>15</td> <td>The size of the matched group in the training step.</td> </tr> <tr> <td>k_est</td> <td>integer</td> <td>50</td> <td>The size of the matched group in the estimation step.</td> </tr> <tr> <td>estimator</td> <td>string</td> <td>‘linear’</td> <td>The method used to estimate the CATE value inside a matched group. The possible options are ‘linear’, ‘mean’ or ‘RF’, which use ridge regression, mean regression, and Random Forest regression, respectively.</td> </tr> <tr> <td>