Americans aren’t just waiting longer to have kids and having fewer once they start—they’re less likely to have any at all.

The global human population has been climbing for the past two centuries. But what is normal for all of us alive today — growing up while the world is growing rapidly — may be a blip in human history.

How do you value a life not yet lived?

It may be time to move on from the Repugnant Conclusion.

Using cleaner fuels such as LPG is essential to reduce rural air pollution and improve health. What can policymakers do to achieve exclusive use of clean fuels in rural India?

The air pollution in India is almost always bad, but in the winter it’s dire. For the last four national elections, Indians voted in late spring. Perhaps that is why national politics has seen so little attention paid to the ever-worsening air pollution. Nowhere in the world are there more deadly particles in the air than north India, where hundreds of millions of people live. But if you only listened to political campaigns and never looked to the sky or took a breath, you might miss the threat altogether.

Fears of impurity continue to steer Indians away from toilets — and towards deadly fecal germs.