Only through focus can you do world-class things, no matter how capable you are.

If you think of global public goods like polio eradication, the kind of risk-taking new approach, philanthropy really does have a role to play there, because government doesn't do R&D about new things naturally as much as it probably should, and so philanthropy's there.

Take agriculture, where we haven't done much, or sanitation; saying, "okay, we will be able to make a really huge effort there." It really energized the foundation and half of what we've gotten done in this last decade is because Warren [Buffett] trusted us.

Microsoft has long hired based on IQ and "intellectual bandwidth."

The AIDS is a disease that is hard to talk about.

Investing for the poor requires participation from the entire community.

Research shows that there is only half as much variation in student achievement between schools as there is among classrooms in the same school. If you want your child to get the best education possible, it is actually more important to get him assigned to a great teacher than to a great school.