You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86 lines
3.5 KiB
Plaintext
86 lines
3.5 KiB
Plaintext
7 months ago
|
{smcl}
|
||
|
|
{* 19nov2002}{...}
|
||
|
|
{hline}
|
||
|
|
help for {hi:leastlikely}{right:(SJ2-4: st0022_1)}
|
||
|
|
{hline}
|
||
|
|
|
||
|
|
{title:List least likely observations}
|
||
|
|
|
||
|
|
{p 8 13}{cmd:leastlikely} [{it:varlist}] [{cmd:if} {it:exp}]
|
||
|
|
[{cmd:in} {it:range}]
|
||
|
|
[{cmd:,} {cmd:n(}{it:#}{cmd:)} {cmdab:g:enerate(}{it:varname}{cmd:)}
|
||
|
|
[{cmdab:no:}]{cmdab:d:isplay} {cmdab:nol:abel} {cmdab:noo:bs}
|
||
|
|
{cmdab:do:ublespace}]
|
||
|
|
|
||
|
|
|
||
|
|
{title:Description}
|
||
|
|
|
||
|
|
{p 4 4 2}For regression models for categorical dependent variables,
|
||
|
|
{cmd:leastlikely} lists the in-sample observations with the lowest
|
||
|
|
predicted probabilities of observing the outcome value that was
|
||
|
|
actually observed. For example, in a model with a binary dependent
|
||
|
|
variable, {cmd:leastlikely} lists the observations that have the lowest
|
||
|
|
predicted probability of {it:depvar=0} among those cases for which
|
||
|
|
{it:depvar=0}, and it lists the observations that have the lowest predicted
|
||
|
|
probability of {it: depvar=1} among those cases for which {it:depvar=1}. The
|
||
|
|
least likely values represent relatively deviant cases that may warrant
|
||
|
|
closer inspection.
|
||
|
|
|
||
|
|
{p 4 4 2}{cmd:leastlikely} works with estimation commands for models of binary
|
||
|
|
outcomes in which option {cmd:p} after {cmd:predict} provides the predicted
|
||
|
|
probability of a positive outcome (e.g., {cmd:logit}, {cmd:probit}), but the
|
||
|
|
dependent variable must be coded as 0 and 1. Likewise, {cmd:leastlikely}
|
||
|
|
works with estimation commands for models of ordinal or nominal outcomes
|
||
|
|
in which option {cmd:outcome(}{it:#}{cmd:)} after {cmd: predict} provides the
|
||
|
|
predicted probability of outcome {it:#}. Exceptions are commands in which the
|
||
|
|
predicted probabilities are probabilities within groups or panels or for
|
||
|
|
"blocked" data; {cmd:leastlikely} will produce an error message if executed
|
||
|
|
after {cmd:blogit}, {cmd:bprobit}, {cmd:clogit}, {cmd:glogit},
|
||
|
|
{cmd:gprobit}, {cmd:nlogit}, or {cmd:xtlogit}.
|
||
|
|
|
||
|
|
{p 4 4 2}{cmd:leastlikely} lists the observation number and the
|
||
|
|
predicted probability (as Prob or as the variable name specified by the
|
||
|
|
{cmd:generate} option). Values of variables in {it:varlist} will also be
|
||
|
|
specified.
|
||
|
|
|
||
|
|
|
||
|
|
{title:Options}
|
||
|
|
|
||
|
|
{p 4 8 2}{cmd:n(}{it:#}{cmd:)} specifies the number of observations to be listed
|
||
|
|
for each outcome. The default is 5. If multiple observations have the same
|
||
|
|
probabilities, more than the specified number will be listed to include all
|
||
|
|
of them.
|
||
|
|
|
||
|
|
{p 4 8 2}{cmd:generate(}{it:varname}{cmd:)} specifies that the probabilities
|
||
|
|
of observing the outcome value that was observed should be stored in
|
||
|
|
{it:varname}. If not specified, the variable name {cmd:Prob} will be created
|
||
|
|
but dropped after the output is produced.
|
||
|
|
|
||
|
|
{p 4 8 2}[{cmd:no}]{cmd:display} forces the format into {cmd:display} or
|
||
|
|
tabular ({cmd:nodisplay}) format. If you do not specify one of these two
|
||
|
|
options, then Stata chooses one based on its judgment of which would be most
|
||
|
|
readable.
|
||
|
|
|
||
|
|
{p 4 8 2}{cmd:nolabel} causes the numeric codes rather than the label values
|
||
|
|
to be displayed.
|
||
|
|
|
||
|
|
{p 4 8 2}{cmd:noobs} suppresses printing of the observation numbers.
|
||
|
|
|
||
|
|
{p 4 8 2}{cmd:doublespace} produces a blank line between each observation in
|
||
|
|
the listing when in {cmd:nodisplay} mode; it has no effect in {cmd:display}
|
||
|
|
mode.
|
||
|
|
|
||
|
|
|
||
|
|
{title:Examples}
|
||
|
|
|
||
|
|
{p 4 8 2}{cmd:. logit low age lwt race2 race3 smoke ptl ht ui}{p_end}
|
||
|
|
{p 4 8 2}{cmd:. leastlikely}{p_end}
|
||
|
|
{p 4 8 2}{cmd:. leastlikely age lwt, n(10) g(prob)}{p_end}
|
||
|
|
|
||
|
|
|
||
|
|
{title:Author}
|
||
|
|
|
||
|
|
{browse "mailto:jfreese@ssc.wisc.edu":Jeremy Freese}
|
||
|
|
Department of Sociology,
|
||
|
|
University of Wisconsin-Madison
|