好高興終於有人討論呢個問題！
其實Recession的定義仍然有好多人爭論緊，以下係The Business Cycle Dating Committee of the National Bureau of Economic Research所提供，亦係Economists會用的定義：
A recession is a period of falling economic activity spread across the economy, lasting more than a few months, normally visible in real GDP, real income, employment, industrial production, and wholesale-retail sales.
但係考試時同學既處理手法就唔同。除左2000的一條LQ外，其他題目都係以一幅圖既升跌決定。因為題目一般都有比到Long-term Growth rate既Trend，考評局以deviation from this trend決定Recession。考試時，除非題目有比其他Hints，否則睇Graph的Shape都穩陣的。
