tobit.hlp

是一个经济学管理应用软件 很难找的 但是经济学学生又必须用到

{smcl}
{* 18mar2005}{...}
{cmd:help tobit}{right:dialog:  {bf:{dialog tobit}}{space 15}}
{right:also see:  {help tobit postestimation}}
{hline}

{title:Title}

{p2colset 5 18 20 2}{...}
{p2col:{hi:[R] tobit} {hline 2}}Tobit regression{p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 16 2}
{cmdab:tob:it}
{depvar} [{indepvars}]
{ifin}
{weight}
{cmd:,}
{opt ll}[{opt (#)}]
{opt ul}[{opt (#)}]
[{it:options}]

{synoptset 20 tabbed}{...}
{synopthdr}
{synoptline}
{syntab:Model}
{p2coldent:* {opt ll}[{opt (#)}]}left-censoring limit{p_end}
{p2coldent:* {opt ul}[{opt (#)}]}right-censoring limit{p_end}
{synopt:{opth off:set(varname)}}include {it:varname} in model with coefficient
constrained to 1{p_end}

{syntab:SE/Robust}
{synopt:{opth vce(vcetype)}}{it:vcetype} may be {opt boot:strap}
or {opt jack:knife}{p_end}

{syntab:Reporting}
{synopt:{opt l:evel(#)}}set confidence level; default is {cmd:level(95)}{p_end}

{syntab:Max options}
{synopt:{it:{help tobit##maximize_options:maximize_options}}}control the
maximization process; seldom used{p_end}
{synoptline}
{p2colreset}{...}
{p 4 6 2}
* You must specify at least one of {opt ll}[{opt (#)}] or {opt ul}[{opt (#)}].
{p_end}
{p 4 6 2}
{opt bootstrap}, {opt by}, {opt jackknife}, {opt rolling}, {opt statsby},
{opt stepwise}, and {opt xi} are allowed; see {help prefix}.
{p_end}
{p 4 6 2}
{opt aweight}s and {opt fweight}s are allowed; see {help weight}.{p_end}
{p 4 6 2}
See {help tobit postestimation} for features available after estimation.{p_end}


{title:Description}

{pstd}
{opt tobit} fits a model of {depvar} on {indepvars} where the censoring values
are fixed.


{title:Options}

{dlgtab:Model}

{phang}
{opt ll}[{opt (#)}] and {opt ul}[{opt (#)}]
   indicate the lower and upper limits for censoring, respectively.
   You may specify one or both.  Observations with
   {depvar} <= {opt ll()} are left-censored; observations with {it:depvar}
   >= {opt ul()} are right-censored; and remaining observations are not censored.
   You do not have to specify the censoring value at all.  It is enough to
   type {opt ll}, {opt ul}, or both.  When you do not specify a censoring
   value, {opt tobit} assumes that the lower limit is the minimum observed in
   the data (if {opt ll} is specified) and the upper limit is the maximum (if
   {opt ul} is specified) .

{phang}
{opth offset(varname)}; see {help estimation options##offset():estimation options}.

{dlgtab:SE/Robust}

{phang}
{opth vce(vcetype)}; see {it:{help vce_option}}.

{dlgtab:Reporting}

{phang}
{opt level(#)}; see {help estimation options##level():estimation options}.

{marker maximize_options}{...}
{dlgtab:Max options}

{phang}
{it:maximize_options}:
{opt iter:ate(#)},
[{cmdab:no:}]{opt lo:g},
{opt tr:ace},
{opt tol:erance(#)},
{opt ltol:erance(#)};
see {help maximize}.  These options are seldom used.

{pmore}
   Unlike most maximum likelihood commands, {opt tobit} defaults to
   {opt nolog}{hline 2}it suppresses the iteration log.


{title:Examples}

{phang}{cmd:. tobit income x1 x2 x3 x4, ul(60000)}{p_end}
{phang}{cmd:. tobit lninc  x1 x2 x3 x4, ul(11)}{p_end}
{phang}{cmd:. tobit lninc  x1 x2 x3 x4, ul}

{phang}{cmd:. tobit amtspt x1 x2 x3 x4, ll(0)}{p_end}
{phang}{cmd:. tobit amtspt x1 x2 x3 x4, ll}

{phang}{cmd:. tobit amtspt x1 x2 x3 x4, ll(0) ul(25000)}{p_end}
{phang}{cmd:. tobit amtspt x1 x2 x3 x4, ll ul}


{title:Also see}

{psee}
Manual:  {bf:[R] tobit}

{psee}
Online:  
{help tobit postestimation};{break}
{helpb intreg},
{helpb cnreg},
{helpb heckman},
{helpb ivtobit},
{helpb oprobit},
{helpb regress},
{helpb "svy: intreg"},
{helpb xtintreg},
{helpb xttobit}
{p_end}