Sam, who is 55 years old and has been a steelworker for 30 years, is unemployed because the steel plant in his town closed and moved to Mexico. Sam is experiencing:

Which of the following conditions ensures that excess profits cannot persist in a perfectly competitive market over the long run?

A) Large number of firms in the industry. B) Outputs of the firms are perfect substitutes for one another. C) Complete information is available to all market participants. D) Ease of entry into the market.

Which of the following groups has the lowest malnutrition rate among children less than 5 years of age?

a. middle-income economies b. low-income economies c. high-income economies d. sub-Saharan African economies e. all the world's economies