Stata 11 help for biprobit

help biprobit dialogs: biprobit seemingly unrelated biprobit svy: biprobit svy: seemingly unrelated biprobit also see: biprobit postestimation -------------------------------------------------------------------------------

Title

[R] biprobit -- Bivariate probit regression

Syntax

Bivariate probit model

biprobit depvar1 depvar2 [varlist] [if] [in] [weight] [, options]

Seemingly unrelated bivariate probit model

biprobit equation1 equation2 [if] [in] [weight] [, su_options]

where equation1 and equation2 are specified as

( [eqname: ] depvar [=] [varlist] [, noconstant offset(varname) ] )

options description ------------------------------------------------------------------------- Model noconstant suppress constant term partial fit partial observability model offset1(varname) offset variable for first equation offset2(varname) offset variable for second equation constraints(constraints) apply specified linear constraints collinear keep collinear variables

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

Reporting level(#) set confidence level; default is level(95) noskip perform likelihood-ratio test 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; seldom used

+ coeflegend display coefficients' legend instead of coefficient table -------------------------------------------------------------------------

su_options description ------------------------------------------------------------------------- Model partial fit partial observability model constraints(constraints) apply specified linear constraints collinear keep collinear variables

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

Reporting level(#) set confidence level; default is level(95) noskip perform likelihood-ratio test 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; seldom used

+ coeflegend display coefficients' legend instead of coefficient table -------------------------------------------------------------------------

+ coeflegend does not appear in the dialog box. indepvars may contain factor variables; see fvvarlist. depvar1, depvar2, varlist, and depvar 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(), noskip, and weights are not allowed with the svy prefix. pweights, fweights, and iweights are allowed; see weight. See [R] biprobit postestimation for features available after estimation.

Menu

biprobit

Statistics > Binary outcomes > Bivariate probit regression

seemingly unrelated biprobit

Statistics > Binary outcomes > Seemingly unrelated bivariate probit regression

Description

biprobit fits maximum-likelihood two-equation probit models -- either a bivariate probit or a seemingly unrelated probit (limited to two equations).

Options

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

noconstant; see [R] estimation options.

partial specifies that the partial observability model be fit. This particular model commonly has poor convergence properties, so we recommend that you use the difficult option if you want to fit the Poirier partial observability model; see [R] ml.

This model computes the product of the two dependent variables so that you do not have to replace each with the product.

offset1(varname), offset2(varname), constraints(constraints), collinear; 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.

noskip specifies that a full maximum-likelihood model with only a constant for the regression equation be fit. This model is not displayed but is used as the base model to compute a likelihood-ratio test for the model test statistic displayed in the estimation header. By default, the overall model test statistic is an asymptotically equivalent Wald test of all the parameters in the regression equation being zero (except the constant). For many models, this option can substantially increase estimation time.

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. These options are seldom used.

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

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

coeflegend; see [R] estimation options.

Examples

Setup . webuse school

Bivariate probit model . biprobit private vote logptax loginc years

Seemingly unrelated bivariate probit model . biprobit (private = logptax loginc years) (vote = logptax years)

Seemingly unrelated bivariate probit model with robust standard errors . biprobit (private = logptax loginc years) (vote = logptax years), vce(robust)

Saved results

biprobit saves the following in e():

Scalars e(N) number of observations e(k) number of parameters e(k_eq) number of equations e(k_aux) number of auxiliary parameters e(k_eq_model) number of equations in model Wald test 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(ll_0) log likelihood, constant-only model (noskip only) e(ll_c) log likelihood, comparison model e(N_clust) number of clusters e(chi2) chi-squared e(chi2_c) chi-squared for comparison test e(p) significance e(rho) rho e(rank) rank of e(V) e(rank0) rank of e(V) for constant-only model e(ic) number of iterations e(rc) return code e(converged) 1 if converged, 0 otherwise

Macros e(cmd) biprobit e(cmdline) command as typed e(depvar) names of dependent variable e(wtype) weight type e(wexp) weight expression e(title) title in estimation output e(clustvar) name of cluster variable e(offset1) offset for first equation e(offset2) offset for second equation e(chi2type) Wald or LR; type of model chi-squared test e(chi2_ct) Wald or LR; type of model chi-squared test corresponding to e(chi2_c) e(vce) vcetype specified in vce() e(vcetype) title used to label Std. Err. e(diparm#) display transformed parameter # 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(predict) program used to implement predict e(asbalanced) factor variables fvset as asbalanced e(asobserved) factor variables fvset as asobserved

Matrices e(b) coefficient vector e(Cns) constraints matrix e(ilog) iteration log (up to 20 iterations) e(gradient) gradient vector e(V) variance-covariance matrix of the estimators e(V_modelbased) model-based variance

Functions e(sample) marks estimation sample

Also see

Manual: [R] biprobit

Help: [R] biprobit postestimation; [R] mprobit, [R] probit, [SVY] svy estimation


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