What is the definition of individual income tax?

The graph below shows how the price of wheat varies with the demand quantity. suppose that lower production costs increases the supply of wheat, such that more wheat is supplied at each price level. the new equilibrium price (after the increase in supply) is

Under a tyranny the power to make a political decision is in the hands of a

In which type of economy are these decisions made by the producers , consumers, and the goverment?