PRINCETON, New Jersey — As I tour America promoting my new book, "The Life You Can Save: Acting Now to End World Poverty," I am often asked if this isn't the wrong time to call on affluent people to increase their effort to end poverty in other countries. I reply emphatically that it is not. There is no doubt that the world economy is in trouble. But if governments or individuals use this as an excuse to reduce assistance to the world's poorest people, they would only multiply the seriousness of the problem for the world as a whole.

The financial crisis has been more damaging for the poor than it has been for the rich. Without minimizing the economic and psychological blow that people experience when they lose their jobs, the unemployed in affluent countries still have a safety net, in the form of social security payments, and usually free health care and free education for their children. They also have sanitation and safe drinking water.

The poor in developing countries have none of these benefits, which proves fatal for an estimated 18 million of them each year. That's a higher annual death toll than during World War II.