October 07, 2009
Danielle Kuczynski contributed to this post
A recent Economist on-line poll asked: Does the world have too many people? There was a predictable response: from their Blackberries or the comfort of their swivel chairs, 80% of Economist voters clicked on yes. You can be sure the respondents are neither the folks having lots of children, nor the ones suffering from the environmental impact of lots of people on the Earth. Yet the commentary accompanying the poll was intriguing, because the same people who agree that the world is over populated don’t agree about what that means, nor what to do about it.
Their disagreement may arise because important basic information about changes in fertility are poorly understood, even among the generally well-informed readers of the Economist. In my mind, the important questions are:
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What’s up with that? Could it be pro-natalist policies in countries worried about declining population? Maybe people recognize the improbability of social insurance to provide for their extended old-age? Regression to the mean of replacement level fertility? A shortage of family planning in the rich world? (just kidding about that one) Is it a natural biological phenomenon?
The Nature authors speculate there may be a biological response to environments that guarantee stability and comfort: people are so comfortable they want to share it with (more) children.
Just as in a real game of connect-the-dots, a picture will emerge as we try to tie together all of these points. Like the responses to the Economist poll, there may be one answer, and many different ways to get to it.
- What are people’s fertility aspirations—that is, how many kids do people want?
- Why are people in different countries seemingly so different in this regard?

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CGD blog posts reflect the views of the authors, drawing on prior research and experience in their areas of expertise. CGD is a nonpartisan, independent organization and does not take institutional positions.