We got a malaria initiative, really a phenomenal time, even though in the early stages there was some uncertainty. Then of course [Barack] Obama, although he had budget constraints, he believed in these things; a lot of new initiatives, including in agriculture.

This social-networking thing takes you to crazy places.

The US spends more on energy R&D than all other countries put together, and I personally consider it quite inadequate. In fact, I would have said we should more than double it, if I thought the absorptive capacity could scale up and if it was actually possible to get to that level.

There certainly is a case to be made that taxes should be more progressive.

The first big effects will be farmers that live on the edge. Today's weather, they barely get by. Their kids, a high percentage are malnourished, and so if you impose more variable weather and more heat, you're getting more floods, more droughts, and during the germination time, the high heat, most crops...do poorly when there's more heat.

But the improvements will happen faster and last longer if we can channel market forces, including innovation that's tailored to the needs of the poorest, to complement what governments and nonprofits do. We need a system that draws in innovators and businesses in a far better way than we do today.

The potential financial reward for building the 'next Windows' is so great that there will never be a shortage of new technologies seeking to challenge it.