{smcl}
{* 8mar2004}{...}
{hline}
help for {hi:nmiss}{right: El }
{hline}

{title:Summarize missing data}

{p 8 17 2}
{cmdab:nmiss} [{it:varlist}] [{cmd:if}]

{title:Description}

{p 4 4 2}{cmd:nmiss} summarizes missing data in a dataset both by rows (i.e., records) and by columns (variables).

{p 4 7 2}1. For each variable in {it:varlist}, {cmd:nmiss} reports the number missing.

{p 4 7 2}2. Considering just the variables in {it:varlist}, {cmd:nmiss} counts the number of missing per record, and reports the distribution. For example: 10 records have 2 missing, 25 records have 5 missing, etc.

{p 4 4 2}{cmd:nmiss} also reports an idiosyncatic {it:missing weight} for each variable, under the heading "MW". In calculating the {it:missing weight}, {cmd:nmiss} uses only the subset of {it:varlist} that have one or more missing.

{p 4 4 2}The {it:missing weight} varies from 0 to 100:
0 if the variable is only missing when every other variable is also missing, and 100 if the variable is only missing when no other variable is missing.

{title:Also see}

{pstd}Contact: {browse "mailto:elliott.lowy@va.gov":Elliott Lowy}