This paper promotes research methods specific to men, the new focus of
fertility and family planning studies (especially in sub-Saharan Afri
ca). I propose a novel marriage categorization based on married men's
intentions to take another wife. The three marriage groups are current
ly monogamous men who intend to remain so, currently monogamous men wh
o intend to become polygynous, and currently polygynous men. The first
analysis demonstrates that typical marriage analyses may misclassify
men who intend to become polygynous. Applications of the marriage tric
hotomy illustrate that men with varying marital intentions have differ
ing desires regarding fertility and family planning.