This is a good and important question. As the paper you linked to indicates, monogamous societies tend to have fewer children than polygynous ones; this, in turn, leads to a host of economic benefits.
But we should distinguish between polygyny and polyamory, which are not at all similar practices. The Trobriand people have a relationship-style that has much more in common with polyamory than polygyny, and this seems to be a direct result of their belief that sex does not cause pregnancy (which they possess because their diet greatly reduces the odds of conception).
While the Trobriand people are not economically well-developed, I think that their relationship-style is a result of that of lack of development and not the other way around. Consider: economic development would lead to a more varied diet, which would then restore conception rates to more normal levels and demonstrate a connection between sex and childbirth; prior to the advent of widely-available contraception, economically developed cultures and the varied diets that accompany them were incompatible with relationship styles similar to the Trobriand people’s.
If this explanation is true (and I acknowledge that the evidence is certainly not conclusive), modern contraceptive techniques might make non-monogamous relationship styles viable in a way that they might not be otherwise. Contraception certainly has the potential to limit population growth, which seems to be polygyny’s greatest economic downside. And we know from the Trobriand example that polyamory-type relationship styles are quite compatible with contraception.
This is a good and important question. As the paper you linked to indicates, monogamous societies tend to have fewer children than polygynous ones; this, in turn, leads to a host of economic benefits.
But we should distinguish between polygyny and polyamory, which are not at all similar practices. The Trobriand people have a relationship-style that has much more in common with polyamory than polygyny, and this seems to be a direct result of their belief that sex does not cause pregnancy (which they possess because their diet greatly reduces the odds of conception).
While the Trobriand people are not economically well-developed, I think that their relationship-style is a result of that of lack of development and not the other way around. Consider: economic development would lead to a more varied diet, which would then restore conception rates to more normal levels and demonstrate a connection between sex and childbirth; prior to the advent of widely-available contraception, economically developed cultures and the varied diets that accompany them were incompatible with relationship styles similar to the Trobriand people’s.
If this explanation is true (and I acknowledge that the evidence is certainly not conclusive), modern contraceptive techniques might make non-monogamous relationship styles viable in a way that they might not be otherwise. Contraception certainly has the potential to limit population growth, which seems to be polygyny’s greatest economic downside. And we know from the Trobriand example that polyamory-type relationship styles are quite compatible with contraception.