Before 1995, Chicago teachers went on strike nine times in two decades, leaving the system in perpetual disarray.

ECONOMIST: Chicago��s schools: Drawn upwards | The

In Ireland's political system, with its perpetual coalitions, that could mean that Sinn Fein holds the balance of power.

ECONOMIST: North meets South

Since all forms of fractional-reserve lending are dependent on the perpetual creation of more and more credit that the system eventually can no longer sustain, it eventually collapses under its own weight.

FORBES: Why MF Global Really Went Bankrupt