我想問美元同港元掛鉤有咩好呀?

Foreign investors would like to invest a place, in which the fluctuation is less. So the linked exchange system of HK$ to US$ can attract more overseas investors invest in HK. Overseas investors can easily make and calculate their own investment budget, and avoid any variance.

RMB appreciation will have advantages and disadvantages to HK.
Advantages - HK people will stay more time in HK for consuming. China tourists will spend much in HK. It will make HK to be more prosperous.
Disadvantages - HK much reply on the import from China. Therefore, the price index will increase heavily because of the RMB appreciation. Also, HK re-export will be affected because the export from China will decrease.

穩定匯價，藉此來穩定經濟貿易不受匯價波動而有所影響！