Stata 11 help for ivprobit

help ivprobit dialogs: ivprobit svy: ivprobit also see: ivprobit postestimation -------------------------------------------------------------------------------

Title

[R] ivprobit -- Probit model with continuous endogenous regressors

Syntax

Maximum likelihood estimator

ivprobit depvar [varlist1] (varlist2 = varlist_iv) [if] [in] [weight] [, mle_options]

Two-step estimator

ivprobit depvar [varlist1] (varlist2 = varlist_iv) [if] [in] [weight] , twostep [tse_options]

mle_options description ------------------------------------------------------------------------- Model mle use conditional maximum-likelihood estimator; the default asis retain perfect predictor variables constraints(constraints) apply specified linear constraints

SE/Robust vce(vcetype) vcetype may be oim, robust, cluster clustvar, opg, bootstrap, or jackknife

Reporting level(#) set confidence level; default is level(95) first report first-stage regression nocnsreport do not display constraints display_options control spacing and display of omitted variables and base and empty cells

Maximization maximize_options control the maximization process

+ coeflegend display coefficients' legend instead of coefficient table ------------------------------------------------------------------------- + coeflegend does not appear in the dialog box.

tse_options description ------------------------------------------------------------------------- Model * twostep use Newey's two-step estimator; the default is mle asis retain perfect predictor variables

SE/Robust vce(vcetype) vcetype may be twostep, bootstrap, or jackknife

Reporting level(#) set confidence level; default is level(95) first report first-stage regression display_options control spacing and display of omitted variables and base and empty cells

+ coeflegend display coefficients' legend instead of coefficient table ------------------------------------------------------------------------- * twostep is required. + coeflegend does not appear in the dialog box.

varlist1 and varlist_iv may contain factor variables; see fvvarlist. depvar, varlist1, varlist2, and varlist_iv may contain time-series operators; see tsvarlist. bootstrap, by, jackknife, rolling, statsby, and svy are allowed; see prefix. Weights are not allowed with the bootstrap prefix. vce(), first, twostep, and weights are not allowed with the svy prefix. fweights, iweights, and pweights are allowed with the maximum likelihood estimator. fweights are allowed with Newey's two-step estimator. See weight. See [R] ivprobit postestimation for features available after estimation.

Menu

Statistics > Endogenous covariates > Probit model with endogenous covariates

Description

ivprobit fits probit models where one or more of the regressors are endogenously determined. By default, ivprobit uses maximum likelihood estimation. Alternatively, Newey's minimum chi-squared estimator can be invoked with the twostep option. Both estimators assume that the endogenous regressors are continuous and are not appropriate for use with discrete endogenous regressors. See [R] ivtobit for tobit estimation with endogenous regressors and [R] probit for probit estimation when the model contains no endogenous regressors.

Options for ML estimator

+-------+ ----+ Model +------------------------------------------------------------

mle requests that the conditional maximum-likelihood estimator be used. This is the default.

asis requests that all specified variables and observations be retained in the maximization process. This option is typically not used and may introduce numerical instability. Normally, ivprobit drops any endogenous or exogenous variables that perfectly predict success or failure in the dependent variable. The associated observations are also dropped. For more information, see the discussion of model identification in [R] probit.

constraints(constraints); see [R] estimation options.

+-----------+ ----+ SE/Robust +--------------------------------------------------------

vce(vcetype) specifies the type of standard error reported, which includes types that are derived from asymptotic theory, that are robust to some kinds of misspecification, that allow for intragroup correlation, and that use bootstrap or jackknife methods; see [R] vce_option.

+-----------+ ----+ Reporting +--------------------------------------------------------

level(#); see [R] estimation options.

first requests that the parameters for the reduced-form equations showing the relationships between the endogenous variables and instruments be displayed. For the two-step estimator, first shows the first-stage regressions. For the maximum likelihood estimator, these parameters are estimated jointly with the parameters of the probit equation. The default is not to show these parameter estimates.

nocnsreport; see [R] estimation options.

display_options: noomitted, vsquish, noemptycells, baselevels, allbaselevels; see [R] estimation options.

+--------------+ ----+ Maximization +-----------------------------------------------------

maximize_options: difficult, technique(algorithm_spec), iterate(#), [no]log, trace, gradient, showstep, hessian, showtolerance, tolerance(#), ltolerance(#), nrtolerance(#), nonrtolerance, from(init_specs); see [R] maximize. This model's likelihood function can be difficult to maximize, especially with multiple endogenous variables. The difficult and technique(bfgs) options may be helpful in achieving convergence.

Setting the optimization type to technique(bhhh) resets the default vcetype to vce(opg).

The following option is available with ivprobit but is not shown in the dialog box:

coeflegend; see [R] estimation options.

Options for two-step estimator

+-------+ ----+ Model +------------------------------------------------------------

twostep is required and requests that Newey's efficient two-step estimator be used to obtain the coefficient estimates.

asis requests that all specified variables and observations be retained in the maximization process. This option is typically not used and may introduce numerical instability. Normally, ivprobit drops any endogenous or exogenous variables that perfectly predict success or failure in the dependent variable. The associated observations are also dropped. For more information, see the discussion of model identification in probit.

+-----------+ ----+ SE/Robust +--------------------------------------------------------

vce(vcetype) specifies the type of standard error reported, which includes types that are derived from asymptotic theory and that use bootstrap or jackknife methods; see [R] vce_option.

+-----------+ ----+ Reporting +--------------------------------------------------------

level(#); see [R] estimation options.

first requests that the parameters for the reduced-form equations showing the relationships between the endogenous variables and instruments be displayed. For the two-step estimator, first shows the first-stage regressions. For the maximum likelihood estimator, these parameters are estimated jointly with the parameters of the probit equation. The default is not to show these parameter estimates.

display_options: noomitted, vsquish, noemptycells, baselevels, allbaselevels; see [R] estimation options.

The following option is available with ivprobit but is not shown in the dialog box:

coeflegend; see [R] estimation options.

Examples

Setup . webuse laborsup

Maximum likelihood estimator . ivprobit fem_work fem_educ kids (other_inc = male_educ)

Two-step estimator . ivprobit fem_work fem_educ kids (other_inc = male_educ), twostep

Saved results

ivprobit, mle saves the following in e():

Scalars e(N) number of observations e(N_cds) number of completely determined successes e(N_cdf) number of completely determined failures e(k) number of parameters e(k_eq) number of equations e(k_eq_model) number of equations in model Wald test e(k_aux) number of auxiliary parameters e(k_dv) number of dependent variables e(k_autoCns) number of base, empty, and omitted constraints e(df_m) model degrees of freedom e(ll) log likelihood e(N_clust) number of clusters e(k_eq_skip) identifies which equations should not be reported in the coefficient table e(endog_ct) number of endogenous regressors e(p) model Wald p-value e(p_exog) exogeneity test Wald p-value e(chi2) model Wald chi-squared e(chi2_exog) Wald chi-squared test of exogeneity e(rank) rank of e(V) e(ic) number of iterations e(rc) return code e(converged) 1 if converged, 0 otherwise

Macros e(cmd) ivprobit e(cmdline) command as typed e(depvar) name of dependent variable e(instd) instrumented variables e(insts) instruments e(wtype) weight type e(wexp) weight expression e(title) title in estimation output e(clustvar) name of cluster variable e(chi2type) Wald; type of model chi-squared test e(vce) vcetype specified in vce() e(vcetype) title used to label Std. Err. e(diparm#) display transformed parameter # e(asis) asis, if specified e(method) ml e(opt) type of optimization e(which) max or min; whether optimizer is to perform maximization or minimization e(ml_method) type of ml method e(user) name of likelihood-evaluator program e(technique) maximization technique e(singularHmethod) m-marquardt or hybrid; method used when Hessian is singular e(crittype) optimization criterion e(properties) b V e(estat_cmd) program used to implement estat e(predict) program used to implement predict e(footnote) program used to implement the footnote display e(marginsok) predictions allowed by margins e(asbalanced) factor variables fvset as asbalanced e(asobserved) factor variables fvset as asobserved

Matrices e(b) coefficient vector e(Cns) constraints matrix e(rules) information about perfect predictors e(ilog) iteration log (up to 20 iterations) e(gradient) gradient vector e(Sigma) Sigma hat e(V) variance-covariance matrix of the estimators e(V_modelbased) model-based variance e(ml_h) derivative tolerance, (abs(b)+1e-3)*1e-3 e(ml_scale) derivative scale factor

Functions e(sample) marks estimation sample

ivprobit, twostep saves the following in e():

Scalars e(N) number of observations e(N_cds) number of completely determined successes e(N_cdf) number of completely determined failures e(df_m) model degrees of freedom e(df_exog) degrees of freedom for chi-squared test of exogeneity e(p) model Wald p-value e(p_exog) exogeneity test Wald p-value e(chi2) model Wald chi-squared e(chi2_exog) Wald chi-squared test of exogeneity e(rank) rank of e(V)

Macros e(cmd) ivprobit e(cmdline) command as typed e(depvar) name of dependent variable e(instd) instrumented variables e(insts) instruments e(wtype) weight type e(wexp) weight expression e(chi2type) Wald; type of model chi-squared test e(vce) vcetype specified in vce() e(vcetype) title used to label Std. Err. e(asis) asis, if specified e(method) twostep e(properties) b V e(estat_cmd) program used to implement estat e(predict) program used to implement predict e(footnote) program used to implement the footnote display e(marginsok) predictions allowed by margins e(asbalanced) factor variables fvset as asbalanced e(asobserved) factor variables fvset as asobserved

Matrices e(b) coefficient vector e(rules) information about perfect predictors e(V) variance-covariance matrix of the estimators

Functions e(sample) marks estimation sample

Also see

Manual: [R] ivprobit

Help: [R] ivprobit postestimation; [R] ivregress, [R] gmm, [R] ivtobit, [R] probit, [SVY] svy estimation, [XT] xtprobit


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