Which of the following would always increase producers' surplus? A shift in the demand curve to the right A price floor A shift in the demand curve to the left A shift in the supply curve to the left Choose the most correct answer by clicking a button, or by typing a letter from the keyboard and pressing the tab key. In a market that can be described with supply and demand curves, a price ceiling below the market clearing price: will raise producer surplus. will lower producer surplus. will leave producer surplus unchanged. may either increase or decrease producer surplus; the result is uncertain. Choose the most correct answer by clicking a button, or by typing a letter from the keyboard and pressing the tab key.