The typical project design time for a large company like IBM - and they keep track of this - is a little over four years.

As you improve health in a society, population growth goes down. You know, I thought it was... before I learned about it, I thought it was paradoxical.

The PC has improved the world in just about every area you can think of. Amazing developments in communications, collaboration and efficiencies. New kinds of entertainment and social media. Access to information and the ability to give a voice people who would never have been heard.

The only role other than paying their taxes, whatever those are, the only role for philanthropy broadly - of which the rich should give disproportionately - the more, the better - and I think there is a positive trend in that direction - there are certain risk-taking things, like trying out a new type of charter school or funding a new kind of medicine.

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.

Every company can choose whether to lead or follow the emerging digital trends.

Microsoft went into orbit because it had a booster rocket attached to it called IBM.