Dr, sorry I could not agree in general although you may be right for those properties you are renting out.
Let me give a very simple example to prove your example is not logically sound
Suppose you own a property same as above HK$ 10MM with USD 3MM mortgage. in your logic;
if interest rate increases by 1%, the rent will be increased by HK$ 30,000 a year
if interest rate increases by 2%, the rent will be increased by HK$ 60,000 a year
if interest rate increases by 3%, the rent will be increased by HK$ 90,000 a year
if interest rate increases by 4%, the rent will be increased by HK$ 120,000 a year
if interest rate increases by 5%, the rent will be increased by HK$ 150,000 a year
if interest rate increases by 10%, the rent will be increased by HK$ 300,000 a year
Do you think the tenant will have the same ability to pay or will be willing to pay?
you have assumed
1) the owner of the property can have the right to determine the amount of rent.
2) The tenant has unlimited ability to match the rent
But in fact, in the real world
1) People do not have unlimited money and are not able to match whatever the landlord want. even though they do not have the power, they will live further, smaller or just simply leave HK
2) Not all landlord has mortgage. It means for those who have mortgage may want to increase rent. but if I don't have a mortgage, I may or may not increase rent as I know the tenant may leave if I increase too much
3) What I want to conclude is this is sth we call demand elasticity (需求彈性). If landlord is not monopoly, no one can charge whatever they want
At the beginning, i said Dr may be able to charge and increase rent relatively as
(1) you hold a lot of quality retail properties that the tenant may need that (low demand elasticity).
(2) They are still earning so much money
(3) You have mortgage and thus you will use this excuse to increase rent
