Notably, though, Ashraf, Field and Lee divided their treatment group into a 'couples' treatment and an 'individuals' treatment. This way, the community health worker visits would involve either consultations with the couple together, or consultations with the women alone. The 'individual' treatment gave women the opportunity to choose whether or not to consult their husbands about opting in or out of very cheap family planning options. And because of this:
Women treated alone were 23% more likely to seek family planning services and 28% more likely to use concealable forms of contraception, leading to a 57% reduction in unwanted births.
And the role of asymmetric information here answers the question about who wants more children, according to one woman who was interviewed:
I put [the voucher for free contraceptives] in the bag for my children's clothes to hide it from my husband. I did not show him the voucher because he does not know that I am using contraceptives.
Because, according to the enumerator:
It seems the husband wants the wife to get pregnant that is why he's not allowing the wife to use contraceptives.
From anecdotal conversations and observations, it almost seems obvious that men want more children than women. I have no idea if this is always true but the authors note that this difference in desired family size might be reduced if we found a way to help men to internalize the costs to women of childbearing and child-raising. Sounds ambitious.