The effect of the price floor is shown in diagram 2 below.
Before the government decided to add the price floor, the market equilibrium was at quantity Qe at the price Pe. The government decides to impose a minimum price of Pmin. This is done to increase the revenue of the farmers of rice, however this creates a new problem. At the new price of Pmin, only Q1 will be demanded, however Q2 will be supplied. If the government decides that it is not going to intervene any further, the quantity that is consumed will actually be reduced from Qe to Q1.
The excess supply that is generated will create problems. As the farmer whave an excess supply from Q1 to Q2. They will try to get rid of the stock, even if it means that they have to sell it at a price that is lower than the market price that is set by the government. To resolve this issue, the government needs to intervene and buy all the stock that cannot be sold. This will reduce the amount of surplus that exists in the market.
Rice is a staple good in Hong Kong; many families depend on rice to make up a majority of their diet. This means that rice has a price inelastic demand, however the rice from Thailand is considered to a luxury product and therefore will be replaced with substitutes from other countries such as