"Is there any evidence that more old people will make special contributions now lacking with an average life expectancy close to 80?"

"And exactly what are the potential social benefits?," writes Daniel Callahan in a NYT op-ed. He's 83 and consumed perhaps more than his proper share of health care resources when he had a 7-hour heart operation to save his life a few years ago.

I have often been struck, at funerals of the elderly, of the common phrase that while the deceased will be missed, he or she led a “full life.” Adding years to a life doesn’t necessarily make it any fuller.

We may properly hope that scientific advances help ensure, with ever greater reliability, that young people manage to become old people. We are not, however, obliged to help the old become indefinitely older. Indeed, our duty may be just the reverse: to let death have its day.

But no, no, no, there are no death panels. Just nudging, withholding, moralizing, disparaging.

What is the social benefit of these old people?

It used to be considered immoral to ask that question.

ADDED: Here's a NYT op-ed from August 2012 also stressing 80 years as the appropriate life-span:

I provided four possible answers [to the question how long would you like to live?]: 80 years, currently the average life span in the West; 120 years, close to the maximum anyone has lived; 150 years, which would require a biotech breakthrough; and forever, which rejects the idea that life span has to have any limit at all....

The results: some 60 percent opted for a life span of 80 years....

This one ends with a quote from Albert Einstein: "As he lay dying of an abdominal aortic aneurysm in 1955, he refused surgery, saying: 'It is tasteless to prolong life artificially. I have done my share, it is time to go. I will do it elegantly.'"