I recently learned of "The Grandmother Hypothesis" (thanks Will). Basically, the hypothesis is that women evolved menopause because, beyond a certain age, it's more effective to invest in their existing children (and grandchildren) than it is for them to continue having children to ensure that their genes persist into future generations. The driving force is the fact that childbirth becomes more dangerous as women age. Neat story.
I believe economist Esther Duflo found behavioral evidence for this theory when she studied the South African Old Age Pension Program although I don't think she realized it (or perhaps she thought it not worth mentioning). She finds that payments to grandmothers improve their granddaughter's health (in terms of weight and height) but payments to grandfathers had no effect. (Interestingly enough, neither has an effect on grandson's health.) Duflo argues "grandmothers are likely to have a stronger incentive than grandfathers to invest in children because they will benefit from them for a longer time" since they are expected to live longer. This is a reasonable explanation but the grandmother hypothesis seems a nice alternative.
I believe economist Esther Duflo found behavioral evidence for this theory when she studied the South African Old Age Pension Program although I don't think she realized it (or perhaps she thought it not worth mentioning). She finds that payments to grandmothers improve their granddaughter's health (in terms of weight and height) but payments to grandfathers had no effect. (Interestingly enough, neither has an effect on grandson's health.) Duflo argues "grandmothers are likely to have a stronger incentive than grandfathers to invest in children because they will benefit from them for a longer time" since they are expected to live longer. This is a reasonable explanation but the grandmother hypothesis seems a nice alternative.
5 comments:
Her hypothesis has a neat implication because it implies there would be a difference between how much grandmothers and grandfathers invest in their offspring. It implies grandfathers have a positive benefit from investing in offspring, but the tests lack enough power to pick this up. The GH, OTOH, gives no reason for grandfathers to invest.
Given expected durations of life for men and women and the assumption that both value offspring the same, you could estimate the benefit per year of offspring.
Also, her hypothesis could be tested by looking at countries where life expectancies have been increasing.
I thought you labor/public people had figured out values for a year of life...
I don't think I follow. You don't know how much $ they're investing in their grandkids so how do you measure how much they value them?
From a layman's point of view: my belief as far as a grandfathers active investment in their children or grandchildren, is that the contribution is passed through to them through the spouse. Therefore, no active contribution from the grandfather is needed or necessary.
Of course, this contribution is acknowledged and expected by the grandfather as the nurturing role of the spouse.
Interesting. Reminds me of the economic concept of crowding out. For example, when government provides health insurance programs it "crowds out" some of private insurance as people stop purchasing it themselves to take up the government program. At the same time, if your hypothesis was correct, I still think we should see grandkids benefiting from extra money that their grandpa's get. I mean, grandma should take it away from him to help the kids, right? Or maybe grandma's not spending any more money on the kids. Maybe she's just able to be healthier and live longer which would benefit the kids if she's a nurturer. In that case, giving money to grandpa wouldn't help if he's not sharing it with grandma.
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