1.In 1968 and 1980, the United States economy experienced a slowdown in productivity incremental. However, since the mid 1980s, the economy has experienced increases in the growth rate in productivity. Can you give reasons why US productivity growth started to increase during the late 1980s and continued throughout the decade of the 1990s?

2. Due to the presence of diminishing returns to capital, doubling the amount of physical capital available for one worker to use will _______.
decrease output by less than a factor of two
increase output by less than a factor of two
increase output by exactly a factor of two
increase output by more than a factor of two

3. Economies with higher growth rates tend to be those that _______.
have large amounts of natural resources
have a stable government that protects property rights
have high levels of government regulation
have all of the above