Which of the following problems are likely to be studied by a macroeconomist and which by a macroeconomist?
a) The rapid growth of Facebook.
b) Why unemployment in the United States rose from 2007 to 2010.
c) Why Japan’s economy grew faster than the U.S. economy in the 1980s, but slower in the 2000s.
d) Why health care costs have risen so rapidly in recent years.