These things balance themselves out, Butler says.

Question: Does increased longevity necessitate population control?

Robert Butler: Well, population control isn't actually occurring I mean in Europe and Japan as populations have lived longer, they have dramatically reduced the birth rate. So, in fact, there is a shrinkage in both Europe and in Japan. Not in the United States because of immigration, but I think it sort of balances itself out. As people live longer, they tend to have fewer babies and as a result they are able to put more resources into the education and the health of the children. So, it has been a very positive thing.

Robert Butler: Well, if you think back to 1900 when the average life expectancy was 47 and you are asking me this question, you could have been thinking we are going to have all those 50 year olds and now we have all those 50 year olds. So, what I think we will see is a healthier, more vigorous population and people in their 70s and 80s than we have had before as a result of medical science and hopefully, people taking better care of themselves.

Recorded on: Mar 17 2008