As the earth spins through space, a view from above the North Pole would encompass most of the wealth of the world - most of its food, productive machines, doctors, engineers and teachers. A view from the opposite pole would encompass most of the world's poor.

After all, despite the economic advantage to firms that employed child labor, it was in the social interest, as a national policy, to abolish it - removing that advantage for all firms.

All of the clean technologies are known, it's a question of simply applying them.

In certain ways, I'm not very different than I was when I was a teenager.

Physicians today, as human beings, are not exempt from the perverse economic pressures created by fee-for-service regimes to see more patients for shorter appointments and order more tests and procedures. If the incentives were changed to pay to foster better health outcomes, I am convinced physician behavior would change over time.

A number of major companies - from PepsiCo to Walmart to U.P.S. - have recognized that corporations have a responsibility to address the causes of climate change before it is too late. We do not have to wait for an international treaty or new regulations to act.

It's unbelievable. I changed the way Barcelona played. Now, Spain have had to change.

One of the most important tasks as a leader in a startup is to pick the right metric to track. This is often referred to as the 'compass metric' because it will be your compass for growth. It's important to note that 'compass metrics' will likely change over the lifetime of a business.