A Second Child or 75 More Years?

A New York Times article yesterday featured the new field of anti-age medicine.  Primarily the goal seems to be for patients to feel and look young in the final decades of life, rather than (necessarily) to add years to their lives, but there are those who think medicine ought to look for ways to add years.  For example, here's ethicist Julian Savulescu on the subject:

Anti-aging research is scandalously under-funded.  In the US, a vast proportion of the funding doled out by the National Institute of Aging is given to research on Alzheimer's disease. According to one estimate (from circa 2004), only about 0.02% of the money spent by the National Institutes of Health (of which the NIA is part) is spent on fundamental aging research. I think funding ought to be perhaps 1,000 times greater. Even if we only hastened progress to a cure for aging by one year, that is brought it forward by one year, that’s about 30 million lives saved. Every year we delay finding a cure, 30 million people die.

I frankly can't imagine anything more strange than trying to give more years to the elderly while millions of children are dying everyday, both here and around the world, from disease and poverty.  Giving more years to an 80 year old is not morally equivalent to giving more years to a 5 year old.

But, just for fun, let's think about this.  Fast forward a couple of hundred years to a time when children aren't dying.  All the more urgent problems have been solved.   There is prosperity everywhere.   One of the ways this has been achieved is that people have learned to limit reproduction.  So the world's population holds constant at 10 billion, year after year.

Researchers are on track to find a cure for aging that will double average lifespan.  The only hitch is that to hold resource use constant, people will have to trade children for years of life. So--the research can be stopped, so people continuing living on average 75 years and having 2 children.  Or it can continue, with the eventually result being that people live on average 150 years and have 1 child.

Just to remove possible distractions, pretend the anti-aging drug won't be available for another 100 years, so the researchers themselves won't be beneficiaries.  Nor do they have any duties to existing people to create or not create the drug.  Which future should they aim for,  "150/1" or business as usual--"75/2"?

I'm reading an article by Russell Blackford that discusses this choice (Journal of Medical Ethics 2009), which was explored in a 1991 article by Peter Singer.  To stay on the same page with them, let's also stipulate that in 150/1, fertility will continue a little later into life, so that people can have that one child at about age 50. Furthermore, in the second 75 years, people will retain the health, appearance, and vigor they had in their 60s and 70s. Otherwise, none of the basic facts of life are different in 150/1.

There are lots of things that bear on which scenario is better overall, but one is which life is better, a 150/1 life or a 75/2 life.  What do you think?  Imagine you're age 30 and you have one child. You're given the choice between having a second child and having your expected life span changed from 75 to 150.  Which would you choose?

More on what Singer and Blackford say later in the week...