__Title__

**[SVY] jkstat** -- Reporting jackknife results

__Syntax__

**jkstat** [*varlist*] [*weight*] [*if*] [*in*] [**,** *options* ]

**jkstat** [*namelist*] [**using** *filename*] [*if*] [*in*] [**,** *options* ]

*options* Description
---------------------------------------------------------------------
**notable** suppress table of output
__noh__**eader** suppress table header
__nol__**egend** suppress table legend
__v__**erbose** display the full table legend

__l__**evel(***#***)** confidence level for CIs
__ti__**tle(***text***)** title for jackknife results

__s__**tat(***vector***)** observed values
__str__**ata(***varname***)** strata
**mse** use MSE formula for variance estimate

*display_options* control column formats
---------------------------------------------------------------------

**fweight**s, **pweight**s, and **iweight**s are allowed with **jkstat**; see weight.

**jkstat** shares the features of all estimation commands, except that
**adjust**, **margins**, **predict**, and **predictnl** are not allowed; see estcom.

__Description__

**jkstat** is a programmer's command that computes and displays estimation
results from jackknife statistics.

**jkstat** computes a variance-covariance matrix using the variables in
*varlist*, assuming the variables contain replicate values from a jackknife
procedure.

If given the **using** modifier, **jkstat** will use the data in *filename* to
perform its calculations while preserving the data currently in memory.
The data in memory are used by default.

The following options may be used when replaying estimation results from
**jkstat**:

__l__**evel(***#***)** **notable** __noh__**eader** __nol__**egend** __v__**erbose** __ti__**tle(***text***)**
*display_options*

For all other options (and qualifiers **using**, **if**, and **in**), **jkstat** requires
a dataset.

__Options__

**notable** prevents displaying the output table. This option implies
**noheader**.

**noheader** suppresses the displaying of the table header. This option
implies **nolegend**.

**nolegend** suppresses the displaying of the table legend. The table legend
identifies the rows of the table with the expressions they represent.

**verbose** requests that the full table legend be displayed. By default,
coefficients and standard errors are not displayed.

**level(***#***)**; see estimation_options.

**title(***text***)** specifies a title to be displayed above the table of
jackknife results; the default title is "Jackknife statistics".

**stat(***vector***)** allows the user to specify the observed value of each
statistic (that is, the value of the statistic using the original
dataset).

**strata(***varname***)** specifies the variable that contains the stratum
identifiers.

**mse** specifies that **jkstat** compute the variance by using deviations of the
replicates from the observed value of the statistics based on the
entire dataset. By default, **jkstat** computes the variance by using
deviations of the pseudovalues from their mean.

*display_options*: **cformat(***%fmt***)**, **pformat(%***fmt***)**, and **sformat(%***fmt***)**; see
**[R] estimation options**.

__Remarks__

Although **jkstat** allows users to specify the observed value and stratum
identifier of each jackknife statistic via the **stat()** and **strata()**
options, programmers may be interested in what **jkstat** uses when these
options are not supplied.

When working from a jackknife dataset, **jkstat** first checks the data
characteristics (see **[P] char**). Here is a list of the characteristics
that **jkstat** understands:

**_dta[jk_version]** identifies the version of the jackknife dataset. This
characteristic is assumed to be empty (not defined) or **1**; otherwise
**jkstat** will behave as if it were empty. This version informs **jkstat**
which other characteristics to look for in the jackknife dataset.

**jkstat** uses the following characteristics from version **1** jackknife
datasets:

**_dta[N]**
**_dta[N_cluster]**
**_dta[command]**
**_dta[jk_svy]**
**_dta[names]**
*varname***[observed]**
*varname***[expression]**

An empty jackknife dataset version implies that the dataset was not
created by **jackknife**. Here the **stat()** option is required. All other
characteristics are ignored.

**_dta[N]** is the number of observations in the observed dataset.

**_dta[N_cluster]** is the number of clusters in the observed dataset.

**_dta[command]** is the command used to compute the observed values of the
statistics.

**_dta[jk_svy]** identifies that the jackknife data came from survey data
when is contains "**svy**"; otherwise, nonsurvey data is assumed. When
this characteristic is appropriately set, it causes **jkstat** to look
for the following other characteristics:

**_dta[N_strata]**
**_dta[N_psu]**
**_dta[strata]**
**_dta[jk_strata]**
**_dta[jk_multiplier]**
**_dta[psu]** **_dta[wtype]** **_dta[wexp]** **_dta[rweights]**

**_dta[names]** identifies the variables containing the jackknife replicates.

*varname***[observed]** is the observed value of the statistic identified by
*varname*. This characteristic may be overruled by specifying the
**stat()** option.

*varname***[expression]** is the expression or label that describes the
statistic identified by *varname*.

The following characteristics are available only when **_dta[jk_svy]** is
"**svy**":

**_dta[N_strata]** is the number of strata in the observed dataset.

**_dta[N_psu]** is the number of PSUs in the observed dataset.

**_dta[strata]** is the name of the variable from the original dataset that
identifies the strata. This characteristic will usually contain the
same variable name as **_dta[jk_strata]**.

**_dta[jk_strata]** is the name of the variable that identifies the strata.
This characteristic may be overruled by specifying the **strata()**
option.

**_dta[jk_multiplier]** is the name of the variable that contains multiplier
values used in the jackknife variance formula. This characteristic
can be overruled by specifying *weight*.

**_dta[psu]** is the name of the variable from the original dataset that
identifies the primary sampling units.

**_dta[wtype]**, **_dta[wexp]**, and **_dta[rweights]** identify the weight type,
expression, and list of replicate weight variable names from the
observed dataset. **_dta[wtype]** and **_dta[wexp]** may also be set for
nonsurvey data, but this is only advisable with **fweight**s; see
weights.

__Stored results__

**jkstat** stores the following in **e()**:

Scalars

**e(N)** sample size
**e(N_strata)** number of strata
**e(N_cluster)** number of clusters (for nonsurvey data)
**e(N_psu)** number of PSUs (for survey data)
**e(N_reps)** number of requested replications

Macros

**e(cmd)** **jackknife**
**e(command)** *command* from **_dta[command]**
**e(exp***#***)** expression for the *#*th statistic
**e(strata)** strata variable
**e(cluster)** cluster variable
**e(missing)** "**missing**" if missing values found, otherwise empty
**e(varlist)** *varlist* or *namelist*
**e(vcetype)** "**Jackknife**" or "**Jknife ***"
**e(vce)** "**jackknife**"
**e(mse)** "**mse**" if **mse** option supplied

Matrices

**e(b)** observed statistics
**e(V)** jackknife variance matrix
**e(jk_b)** jackknife means