Over the past fifty years, there has been substantial closure of the gap in real GDP per person between which of the following groups of countries?

Economists who favor bigness in firms point to which of the following to support their argument?

a. economies of scale b. perfect competition c. need for antitrust d. advantages of marginal cost pricing e. constant returns to scale

"Hydraulic fracking" has led to all of the following, except:

A. Strengthening the argument for subsidizing alternative energy sources B. Making the U.S. a major producer of natural gas in the world C. Making the U.S. a major oil or petroleum producer in the global market D. Creating a heated debate over its environmental ramifications