Generating a variable

[Sonia Zam]

I want to generate variable that indicate if individuals continue to participate in a program at age of 72 or after. For example, if an individual participated in the program at age 69 and 73 then a value of 1 should be given, if an individual participated only before the age of 72 then a value of 2 should be given and if an individual participated only at the age of 72 or after then should be given a value of 3.

A sample of data structure is below.

e.g.


ID age Participation_date

B001 68 05nov2012

B001 70 07may2015

B001 72 09jun2017

B002 67 28nov2011

B002 68 22oct2012

B002 69 25nov2013

B002 70 10nov2014

B002 71 14dec2015

B002 72 12dec2016

B003 73 25feb2012

B003 75 08oct2013

B003 77 12feb2016

B004 76 16jun2012

B004 78 22may2014

B005 68 17nov2012

B006 76 12mar2013

B006 78 29apr2015

B007 72 22jun2012

B007 74 04aug2014

B008 71 29jan2013

B008 73 04mar2015

B008 75 30mar2017

B009 72 28jan2015

B010 71 28feb2012

B010 74 03jun2014

B011 73 04feb2013

B011 76 17sep2015

Thanks for the help

[Nick Cox]

bysort ID (age) : gen wabted = cond(age[1] >= 72, 3, cond(age[_N] < 72, 2, 1))

[Sonia Zam]

Thank you so much Nick.