In economics, when you put together a highly elastic thing and a highly inelastic thing, you create extraordinary potential for turbulence, volatility, and for unstable prices.

Rising inequality can create a more highly leveraged economy, and it can then make the economy vulnerable to a crash like 2008.

The richer people, when they get another $100,000, or another million, or 10 million, don't tend to spend it as much as the poorer people would if they got another $100 or $1,000 or $5,000. All the empirical evidence suggests that the rich tend to consume a lower proportion of income than middle and lower-income people.

The probability that we face global warming caused by fossil fuels is now so overwhelming that it is legitimate to doubt the motives of those who deny it

If your credit is going to grow at 10-15 percent per year in order to get your 5 percent GDP growth per year, eventually you're going to have a problem. This isn't a stable system.

We need to move beyond the demonisation of overpaid traders ... In finance and economics, ill-designed policy is a more powerful force for harm than individual greed or error.

The capitalist system is not delivering those decade-after-decade increases it promised. We're not where we should be in terms of our national economies. We don't know how to get out of this malaise and I think we now have to consider more radical policies.

Instability mostly comes from the interface between the fact that the banks (or shadow banks) can create credit, money, and purchasing power in infinite quantities if we don't constrain them, and the fact that credit is primarily created to fund the purchase of urban real estate and land, which is somewhat fixed in supply.

In absolute terms, we may have to look at restricting the number of flights people take.