For which of the following goods is the income elasticity of demand likely highest?

In perfect competition, ________

A) there are restrictions on entry into the market B) firms in the market have advantages over firms that plan to enter the market C) only firms know their competitors' prices D) there are many firms that sell identical products

Suppose the price of beef declines by $0.50 per pound at the supermarket. Consumers of beef immediately increase their purchases of beef. This illustrates:

a. the fact that beef is an inferior good. b. the cross-elasticity effect of a price decrease. c. the substitution effect of a price decrease. d. the fact that beef is an economic bad. e. the income effect of a rise in price.