Estimate a equation in a panel structured workfile using the difference-in-difference estimator.

Syntax

did(options) y [x1] [@ treatment]

List the dependent variable, followed by an optional list of exogenous regressors, followed by an “@” and then the binary treatment variable. You should not include a constant in the specification.

Options

coef=arg | Specify the name of the coefficient vector. The default behavior is to use the “C” coefficient vector. |

prompt | Force the dialog to appear from within a program. |

p | Print results. |

Examples

did asmrs @ post

estimates an equation by difference-in-difference with ASMRS as the outcome variable, and POST as the treatment variable.

did lemp lpop @ treated

estimates an equation by difference-in-difference with LEMP as the outcome variable, TREATED as the treatment variable, and LPOP as an exogenous regressor.

Cross-references

See
“Difference-in-Difference Estimation” for a discussion of difference-in-difference models.