SSS 2011-02-28（在线收听）

This is Scientific American's 60-Second Science. I'm Steve Mirsky. Got a minute?

"There have been tremendous declines in fertility. The key has been the prevention of unwanted births, really around the globe."

John Casterline directs the Initiative in Population Research at Ohio State. He spoke at the AAAS meeting in Washington on February 20th.

"This is a really remarkable public health success story that I think doesn't get featured with all the other kinds of success we've had in eliminating some diseases and so forth. But the story is not complete yet. There's still a considerable amount of unintended fertility, especially in some parts of Asia and Africa."

"What are the prospects now looking forward that we can address that level of unwanted fertility? Well, on a hopeful side we know that there are very high levels of unmet need for family planning. So if we were to satisfy that unmet need, various analyses show we would go a long way towards achieving the reduction in birth rates that are required to achieve global population stabilization."

"On the less hopeful side, we've been successively underinvesting in family planning internationally. As the number, actually, of women in need has grown, the investment has declined."