需求和供給改變問題一條~~

Let me try:
Governement would impose a price ceiling on RAM import price next month.
(a) case 1: price ceiling is below the import price
If the import price of RAM is above the price ceiling, exporter would not willing to sell RAM to HK (ie. losing momeny for each deal). That's mean the RAM supply would be dropped (ie. drop in supply) next month. The price of RAM would be increased next month. Or, a black market of RAM (with higher RAM price) would be created.
If there is a general expectation of price increase in RAM next month, people tend to purchse RAM now. Increasing demand of RAM in current month is expected. The price of RAM would also be increased in current month given the supply of RAM is fixed in short-run.

(b) case 2: price ceiling is above the import price
If the import prie of RAM is below the price ceiling, it does not affect the RAM market. The supply of RAM would not be affected (ie. exporter is willing to sell RAM in HK). The price of RAM will keep at current market price next month.
Given the general expectation of RAM price is stable / unchange, it has no impact on current month RAM market (ie. the price of RAM is stable / unchange).

我大致同意danny_chen_1982所說的意見，電腦記憶體價格在本月一定會跌，但有一點我太應同，就是，我相信本月交易量不會下跌，因為售賣電腦記憶體的商人，好大機會會在本月促銷手上所有的電腦記憶體，因為他們知道，下月會有更便宜的電腦記憶體進入市場競爭，因此，他們促銷所有電腦記憶體的產品，導致交易量有增無減．

由於下月買電腦記憶體會比現在買便宜, 消費者會傾向等待下個月才購買, 因此本月的電腦記憶體的需求下跌,本月需求下跌導致本月的電腦記憶體價格及交易量皆下跌.