I think that the Government should have measures to control quantities of rubber, domestic. The volume is too high, it's needs exceed the purchase price of the tires resulted in decreased.
I think the government should take measures to control the supply of the domestic rubber. Not so with the volume too high Excess demand As a result, prices fell.
I think the government should control measures on yield of domestic rubber, do not have a high volume too the purchase requirement. Therefore, the price of rubber decreased.