When an industry is a natural monopoly:

a. it is characterized by constant returns to scale
b. it is characterized by diseconomies of scale
c. a larger number of firms may lead to a lower average cost
d. a larger number of firms will lead to a higher average cost

John and daphne are saving for their daughter ellen's college education. ellen just turned 10 at (t = 0), and she will be entering college 8 years from now (at t = 8). college tuition and expenses at state u. are currently $14,500 a year, but they are expected to increase at a rate of 3.5% a year. ellen should graduate in 4 years--if she takes longer or wants to go to graduate school, she will be on her own. tuition and other costs will be due at the beginning of each school year (at t = 8, 9, 10, and 11).so far, john and daphne have accumulated $15,000 in their college savings account (at t = 0). their long-run financial plan is to add an additional $5,000 in each of the next 4 years (at t = 1, 2, 3, and 4). then they plan to make 3 equal annual contributions in each of the following years, t = 5, 6, and 7. they expect their investment account to earn 9%. how large must the annual payments at t = 5, 6, and 7 be to cover ellen's anticipated college costs? a. $1,965.21b. $2,068.64c. $2,177.51d. $2,292.12e. $2,412.76

The former chairman of the federal reserve, alan greenspan, used the term "irrational exuberance" in 1996 to describe the high levels of optimism among stock market investors at the time. stock market indexes such as the s& p composite price index were at an all-time high. some commentators believed that the fed should intervene to slow the expansion of the economy. why would central banks want to clamp down when the economy is growing? a. to block the formation of unsustainable speculative asset bubbles. b. to curtail excessive profits in the banking system. c. to prevent inflationary forces from gathering momentum. d. all of the above. e. a and c only.

How an absolute advantage might affect a country's imports and exports?