Changes

:::<math>\frac{-Q}{P}X\frac{P}{Q}</math>

:::<math>\frac{-Q}{P}X\frac{P}{Q}</math>

and thus P_ed= -1.  By convention, because price elasticity is always negative, the negative sign is dropped and we have our answer:  elasticity is 1.

and thus P_ed= -1.  By convention, because price elasticity of demand for one good is always negative, the negative sign is dropped and we have our answer:  price elasticity is 1. (Price cross-elasticity of demand may be positive or negative, depending on whether the two goods are substitutes or complements.)

9.  Provide, in your own words, the best definition of "public good" that you can.

9.  Provide, in your own words, the best definition of "public good" that you can.

:The correct answer is shortage of 600. A shortage occurs because a price ceiling increases demand, without adjusting output- in fact, output will ... decrease, because producers are now making less money. Specifically, the shortage can be measured by measuring the quantity between where a line representing the price ceiling intersects the supply curve and demand curve.  (Addison)

:The correct answer is shortage of 600. A shortage occurs because a price ceiling increases demand, without adjusting output- in fact, output will ... decrease, because producers are now making less money. Specifically, the shortage can be measured by measuring the quantity between where a line representing the price ceiling intersects the supply curve and demand curve.  (Addison)