__SAS Code for Part A.__

**sort two data sets by mother id, and then merge;*

data child;

set x;

**rename mother id to match name of variable in mom dataset;*

momid = C0000200;

proc sort; by momid;

**data mom; set y; **

**data childmom; merge child mom; by momid; **

__SAS Code for Part B.__

**create variables for age and year of last interview for mom;*

**note that we name these variables to start with an "m" to denote that these are variables for the mother;*

if R0898310 gt 0 then do;

m_age_lint = R0898310;

m_year_lint = 1982;

end;

**repeat for all intervening years; *

**note that we redefine these variables each time "age at interview" is reported to find the age at last interview;*

…

if T0989000 gt 0 then do;

m_age_lint = T0989000;

m_year_lint = 2006;

end;

**create variable indicating that mom had a teen birth;*

**note that we define this variable only for women ages 18 and over;*

if m_age_lint ge 18 then do;

**age at 1st birth is between 0 and 17*;

if (m_year_lint = 1982 and R0898840 gt 0 and R0898840 lt 18) then m_teenbirth = 1;

**age at 1st birth is 18 or greater, so no teen birth;*

if (m_year_lint = 1982 and R0898840 ge 18) then m_teenbirth = 0;

**never gave birth, so no teen birth; *

if (m_year_lint = 1982 and R0898840 = -998) then m_teenbirth = 0;

**repeat for each year-- this strategy lets us define these variables using data reported at the last interview;*

…

if (m_year_lint = 2006 and T0996200 gt 0 and T0996200 lt 18) then m_teenbirth = 1;

if (m_year_lint = 2006 and T0996200 ge 18) then m_teenbirth = 0;

if (m_year_lint = 2006 and T0996200 = -998) then m_teenbirth = 0;

end;

**using data through 2006;*

**m_teenbirth (mean = .201, N = 11463);*

**m_year_lint (mean =2002, N = 11465);*

**m_age_lint (mean =41.4, N = 11465);*

__SAS Code for Part C.__

**restrict sample to female young adults, drops 8322 observations using data through 2006;*

**sample size is now 3147;*

if Y0677400 = 2;

**create variables for age and year of last interview for young adult;*

**note that we name these variables to start with "y" to denote that these are variables for the young adult;*

if Y1205100 gt 0 then y_year_lint = Y1205100;

if y_year_lint = 1994 then y_age_lint = Y0342400;

**repeat for each year--this strategy lets us define these variables using data reported at the last interview;*

…

if y_year_lint = 2006 then y_age_lint = Y1948500;

**create variable indicating that female young adults who are 18 or over had a teen birth;*

if y_age_lint ge 18 then do;

if (Y1211100 gt 0 and Y1211100 lt 18) then y_teenbirth = 1;

if (Y1211100 ge 18) then y_teenbirth = 0;

if (Y1211100 = -998) then y_teenbirth = 0;

end;

**Final Statistics from Program: Data through 2006 survey;*

**m_teenbirth (mean = .249, N = 3147);*

**y_teenbirth (mean = .137, N = 2419)—smaller sample size because only created for those at least 18;*

**y_year_lint (mean = 2006, N = 3147)*

**y_age_lint (mean = 21.3, N = 3147)*

**m_year_lint (mean = 2005, N = 3147)*

**m_age_lint (mean = 44.6, N = 3147)*