I think given all the different imperatives - getting energy to Africa, security of energy, climate change, that we should be spending half as much as we spend on health, which will get you all the way up to $15 billion - the health people don't like it when things get compared to their number.

In 1990, one in 10 children died before the age of five. That's now down to one in 20, and vaccines were the single biggest factor in that. Had it stayed at 10 percent, 122 million more children would have died.

I believe it’s not only possible to eradicate malaria; I believe it’s necessary. Ultimately, the cost of controlling it endlessly is not sustainable. The only way to stop this disease is to end it forever.

The most interesting biofuel efforts avoid using land that's expensive and has high opportunity costs. They do this by getting onto other types of land, or taking advantage of byproducts that aren't used in the food chain today, or by intercropping.

No one person controls Microsoft. The board and the shareholders decide whether they want to have me as CEO.

People in business understand paying money to be more efficient. You can bootstrap markets where the devices are too expensive at first because these are so valuable to some people.

Philanthropy should be voluntary.