People tend to think that paying a debt is like going out and buying a car, buying more food or buying more clothes. But it really isn't. When you pay a debt to the bank, the banks use this money to lend out to somebody else or to yourself. The interest charges to carry this debt go up and up as debt grows.

Mathematically, debts grow exponentially at compound interest. Banks recycle the interest into new loans, so debts grow exponentially, faster than the economy can afford to pay.

Mr. Trump wants to turn the U.S. economy into the kind of real estate development that has made him so rich in New York. It will make his fellow developers rich, and it will make the banks that finance this infrastructure rich, but the people are going to have to pay for it in a much higher cost for transportation, much higher cost for all the infrastructure that he’s proposing. You could call Trump's plan "public investment to create private profit". That's really his plan in a summary.

Canada is a malstructured. You could almost call it a failed economy, except that its natural resources are so rich that everybody can get wealthy off making holes in the ground and digging up the oil and polluting the environment.

Almost all of the demand for oil that suddenly pushed prices up was speculative demand. People began to speculate not only in stocks and bonds and real estate, but also in commodities. The market went up for old tankers, which were used simply to store oil in. A lot of the oil was simply being stored for trading, not used.

The ideological foundation of today's business schools is that economic control should be shifted out of government hands into those of financial managers - that is, Wall Street.

So the political choice today is much like the 1930s, when the global economy also broke down. The choice is between nationalism and populism on the right, or socialism reviving what used to be left-wing politics.