Giving and taking between husband, wives, and co-wives is this week's 'chart of the week' at the American Economic Association. 

Over 40 percent of women in many West African countries are in polygynous marriages—the practice of having more than one wife. This has created a challenge for development programs that wish to help all family members equally, especially children.  According to a research paper published in the April issue of the American Economic Journal: Applied Economics, polygynous husbands and wives cooperate less than monogamous ones and may contribute resources to the household with less altruistic motives.

Professor Abigail Barr (University of Nottingham, CeDEx and Co-Investigator on the NIBS 1 project) with co-authors, Marleen Dekker, Wendy Janssens, Bereket Kebede, and Berber Kramer conducted an experiment in Nigeria with 448 individuals who were in either monogamous marriages or polygynous marriages involving two wives.

Abigail explains, " Using a carefully designed series of public goods games, we compare, across monogamous and polygynous households, the willingness of husbands and wives to cooperate to maximize household gains.  Compared to monogamous husbands and wives, polygynous husbands and wives are less cooperative, one with another, and co-wives are least cooperative, one with another.  The husbands' and wives' behavior in a corresponding series of inter-household games indicates that these differences cannot be attributed to selection of less cooperative people into polygyny. Finally, behavior in polygynous households is more reciprocal and less apparently altruistic".

The full paper can be viewed online.