Regulating and taxing marijuana would simultaneously save taxpayers billions of dollars in enforcement and incarceration costs, while providing many billions of dollars in revenue annually.

The scope for improvement is infinite, precisely because perfection is unattainable.

We must recognize that as the dominant power in the world we have a special responsibility. In addition to protecting our national interests, we must take the leadership in protecting the common interests of humanity.

By creating the European Central Bank, the member states exposed their own government bonds to the risk of default. Developed countries that issue bonds in their own currency never default, because they can always print money. Their currency may depreciate, but the risk of default is absent.

The lower interest rates fueled housing and consumption booms in countries such as Spain and Ireland. At the same time, Germany, struggling with the burdens of reunification, tightened its belt and became more competitive. All this led to a wide divergence in economic performance. Europe became divided into creditor and debtor countries.

If investing is entertaining, if you're having fun, you're probably not making any money. Good investing is boring.

I passionately disagreed with Treasury Secretary Hank Paulson's plan to bail out the banks by using a public fund called the Troubled Asset Relief Program (TARP) to help banks take toxic assets off their balance sheets. I argued that it would be much better to put the money where the hole was and replenish the equity of the banks themselves.