Among which of the following will cause an increase in producer surplus?

A. buyers expect the price of the good to be lower next month b. the price of a substitute increases c. income increases and buyers consider the good to be inferior d. the imposition of a binding price ceiling in the market

Which of the following causes a shortage of a good? A. a binding price floor b. a tax on the good c. a binding price ceiling d. More than one of the above is correct.