{smcl}
{* 24mar2002}{...}
{hline}
help for {hi:xtsumcorr}
{hline}
{title:Summarize xt data}
{p 8 14}{cmd:xtsumcorr} [{it:varlist}] [{cmd:if} {it:exp}] [{cmd:,} {cmd:i(}{it:varname}{cmd:)} ]
{p}{cmd:by} {it:...} {cmd::} may be used with {cmd:xtsumcorr}; see help {help by}.
{title:Description}
{p}If you have not read help for {help xtsum}, please do so now.
{p}{cmd:xtsumcorr} is an augmented version of {cmd:xtsum} that
computes corrected version of within-panel and between-panel standard
deviations.
{p} The within-panel standard deviation is the same as that in
{cmd:xtsum}, except that the divisor is (N - sum T_i) instead of (N -
1), where N is the total sample size and T_i is the within-panel
sample size. This estimator is unbiased for the within-panel variance
and is analagous to that reported in {cmd:xtreg , fe}. The overall
standard deviation is computed as half of the average of the squared
differences between observations on different panels. The
between-panel standard deviation is computed as the square root of the
overall variance minus the within-panel variance.
{title:Example}
{inp:. iis patid}
{inp:. xtsumcorr bp}
{title:Also see}
Manual: {hi:[R] xtsum}
{p 0 19}On-line: help for {help xtsum}, {help xt}{p_end}