{smcl}
{* 24feb2004}{...}
{hline}
help for {hi:grouping}{right:(SJ6-4: st0112)}
{hline}

{title:Calculate grouping indicator for linked employer-employee data}

{p 8 16 2}
{cmdab:grouping} {it:newvar}{cmd:,} {cmdab:i:var(varname)}
{cmdab:j:var(varname)}


{title:Description}

{pstd} {cmd:grouping} calculates a unique group number for each firm
and each individual in a linked employer-employee dataset.  Each firm
is indexed by the {cmd:jvar} variable, and each individual is indexed
by the {cmd:ivar} variable.  The variable {it:newvarname} stores the
resulting group numbers.

{pstd} A group contains all the individuals who have ever worked for any
of the firms in a group and all the firms at which any of the workers
were employed.  Thus, in most reasonable cases, the first group will
contain almost all workers and firms. To be in a separate group, a firm
must have employed no workers who ever worked for any firm in another
group.  A firm that experiences no turnover will be in a group of its
own.

{pstd} The algorithm for computing the groups is based on that given by
Abowd, Creecy, and Kramarz (2002).


{title:Reference}

{phang}
Abowd, J., R. Creecy, and F. Kramarz. 2002. Computing person
and firm effects using linked longitudinal employer-employee data.
Technical Report 2002-06, U.S. Census Bureau.
{browse "http://lehd.dsd.census.gov/led/library/techpapers/tp-2002-06.pdf"}.


{title:Authors}

{pstd}
Richard Upward{break}
School of Economics{break}
University of Nottingham{break}
richard.upward@nottingham.ac.uk

{pstd}
Thorsten Schank{break}
Volkswirtschaftliches Institut {break}
Friedrich-Alexander-University Erlangen-Nuremberg{break}
thorsten.schank@wiso.uni-erlangen.de
{p_end}