Many people use the Euro debt crisis (歐債危機) as examples in their essays. Here are some articles that will give you more information on the topic:
歐債危機的起因:
私人部門的長期過度負債行為
Companies and mortgage borrowers took out loans but are unable to pay them back.
政府部門失職與制度缺陷 (歐洲式社會福利拖累)
A massive amount of government borrowing and irresponsible spending, especially Greece!
國民無能力還債不願消費
Citizens are unable to pay back their loans and unwilling to consume.
出口產品無競爭力
Exports are uncompetitive as wages are high in Europe.
and many more...
Sources:
Eurozone crisis explained - http://www.bbc.co.uk/news/business-16290598
歐債危機起因和根源 - http://big5.qstheory.cn/special/2011dd/ozwj/qy/
全球國債矛盾與無解 三分鐘內解釋完畢 -
http://www.youtube.com/watch?v=7s44vuVR0BY