It's not often I agree with Megan McArdle, but she's absolutely right when she says that at 85, the Pope is far too old to be doing a job as mentally taxing as running the Catholic Church. This troubling chart from Marginal Revolution shows just how badly cognitive ability declines in the general population over time. And this is not a trick question designed to catch people out. It's straight up division:
Anyone who has elderly grand parents or parents knows this all too well. How many of you would be comfortable with a relative over the age of 75 taking on full time work in a highly stressful job?
The chart shows a fairly slow rate of decline up until the mid to late 70's where the ability to do very simple mathematical problems drops off incredibly quickly. There are of course lifestyle factors involved here, and advances in the understanding of neuro plasticity (the ability of the brain to adapt and grow) are helping prolong mental sharpness. But age is something we simply can't fight (at least for now), and having an 85 year old man in charge of a vastly complex organization reeling from scandal after scandal is tantamount to serious negligence.
As I argued yesterday, it's entirely possible that Ratzinger is leaving due to the sex scandals in the church. Perhaps 10 years ago he could have handled the pressure better and found a way to survive the relentless assaults coming from former abuse victims and angry parents. But it's clear at 85 he can't do it any more.