Table 1.

Variables used for analysis

Study Variables	Operational Definitions and Coding
Fertility desire	0 = Equal desire, 1 = Husbands desire more and 2 = Wives desire more
Type of marriage	1 = Monogamy and 2 = Polygyny
Region	According to respective regions of respondents as provided by NDHS, 1 = North Central, 2 = North East, 3 = North West, 4 = South South, 5 = South East and 6 = South West
Age difference	Self-reported ages of couples coded as 1 = same age (less than 3 years younger or older), 2 = husbands older (husbands more than 3 years older) and 3 = wives older (wives more than 3 years older)
Difference in Education	Self-reported number of years spent in school by couples coded as 1 = same education (for couples who spent the same number of years in school), 2 = husbands more educated (husbands spent more years in schools compared to wives) and 3 = wives more educated (wives spent more years in schools compared to husbands)
Wealth Index	According to household index, wealth is classified into 5 categories by NDHS, 1 = Poorest, 2 = Poorer, 3 = Middle, 4 = Richer and 5 = Richest
Residence	According to NDHS classification, 1 = urban and 2 = Rural
Religion	1 = Christianity, 2 = Islam and 3 = Traditional religionists and others
Work Status of Couples	1 = Both are working and 0 = Others (it involved couples who indicated that either were working or that both were not working)
Children Ever Born	1 = 0, 2 = 1–2, 3 = 3–4 and 4 = 5+
Use of Contraceptive	1 = Using and 2 = Not using