| HeckmanEM | Fit the Normal or Student-t Heckman Selectio model. |
| HeckmanEM.criteria | Model selection criteria for the Heckman Selectio model |
| HeckmanEM.envelope | Envelope for the Heckman Selectio model. |
| HeckmanEM.infomat | Standard error estimation for the Heckman Selectio model by the Information Matrix. |
| rHeckman | Generate data from the Heckman Selectio model (Normal or Student-t). |