If the quantity demanded changes proportionately the same as price, demand is said to be

If a seller enjoys a producer surplus of $30 when he sells a good for $79, his reservation value for the good is ________

A) $30 B) $49 C) $79 D) $109

Define the following terms and explain their importance to the study of economics:

a. regressive tax b. proportional tax c. progressive tax d. direct tax e. indirect tax