* DHS User Forum inquiry

* "I would like to calculate the mean age at childbearing by birth order, 
*   for 3 year period preceding the survey. 
* Are there any resources on how to calculate such indicator in Stata?"

* Response by Tom Pullum, tom.pullum@icfi.com, January 10, 2014

* dob is the child's date of birth 
* doi is the mother's date of interview
* cmc is century month code
* bord is birth order

* open any BR file

gen dob_cmc=b3
gen doi_cmc=v008

* drop births in the month of interview (standard practice)
drop if dob_cmc==doi_cmc

* restrict births to the 36 months before the interview
keep if doi_cmc-dob_cmc<=36


gen age_of_mother_at_dob=(dob_cmc-v011)/12

gen birth_order=bord
replace birth_order=12 if bord>12

format age_of_mother_at_dob %6.2f

tab birth_order [iweight=v005/1000000]

tab birth_order [fweight=v005], summarize(age_of_mother_at_dob) nofreq noobs