Europe's debt crisis became much worse this week. The International Monetary Fund promised to increase a Euro45 billion (HK$461 billion) aid package for Greece - the hardest-hit eurozone country - to as much as Euro120 billion over three years. But the debt disease seemed to be spreading.

After downgrading Greek debt to 'junk status', a major agency that judges the safety of debt, Standard & Poor's, then downgraded Portugal and Spain.

Spain's economy, at four times the size of Greece, is considered by many to be too big to rescue. One senior economist said Greece would not be able to pay back bail-out money. This shows a limit to how much wealthy European Union countries can help nations that cannot pay their debts.