COHABLASTSTARTCMC is a 4-digit variable that represents the century-month value (months since 1900) when the woman began living with her current or most recent partner or husband. The following values represent not in universe or missing cases:
9995 = Not interviewed (female questionnaire)
9998 = No response or missing
9999 = NIU (not in universe)
COHABLASTSTARTCMC reports the century month code (CMC) for when the respondent started living with her current or most recent husband or partner.
Note that January is consistently the most common month across samples (see COHABLASTSTARTMO). Due to the data entry format of the survey, if a respondent reported a year but not a month for when she started living with her current or most recent husband or partner, January was the default month.
Enumerators were instructed to enter the date as January 1st, 2020 (January 1st, 2030 for samples in 2019 or after) if the respondent did not give a response to the associated survey question. IPUMS has recoded these cases to "No response or missing."
Century month codes (CMC) are particularly useful for checking the consistency of dates, calculating intervals between events, and imputing dates when the information for an event is missing or partially complete.
Century month codes (CMC) are calculated by multiplying by 12 the difference between the year of an event and 1900. The year 1900 was chosen as the reference period because all of the relevant events for PMA2020 occurred during the twentieth or twenty-first centuries. The month of the event is added to the previous result, using the following formula:
CMC = (Year - 1900) * 12 + Month
For example, the CMC for June 2002 is:
CMC = (2002 - 1900) * 12 + 6 = 1230
In other words, 1,230 months have elapsed between January 1900 and June 2002. Starting with CMC figures, one can calculate the month and year using the following formulas:
Year = int( ( CMC - 1 )/12 ) + 1900
[int(x) is the integer part of x]
Month = CMC - ( ( Year - 1900 ) * 12 )
The information above is based on "Online Guide to DHS Statistics" (Rutstein and Rojas, 2006).
The question associated with this variable was included in the female questionnaire.
- Women aged 15 to 49 who have ever married.
- Burkina Faso: 2014-2018, 2020
- Congo (Democratic Republic): 2014-2019
- Cote d'Ivoire: 2017-2018
- Ethiopia: 2014-2019
- Ghana: 2013-2017
- India: 2016
- Indonesia: 2015-2016
- Kenya: 2014-2019
- Niger: 2015-2018
- Nigeria: 2014-2019
- Uganda: 2014-2015