If income doubles and the prices of all goods remain the same, the budget line will shift outward by 50 percent along each axis

Which of the following statements about demand is true?

a. The demand curve for a group of consumers in a market is simply the horizontal summation of each individual's demand. b. The single demand curve shows the quantity of a good that people will buy, allowing all factors (price, income, expected future prices, etc.) to vary. c. An increase in income will cause a person to move down and to the right along her demand curve. d. All of the above are true.

Researcher Terry Anderson claims that with respect to the supply of water, trading it would be

a. wrong and counter-productive. b. essentially impossible due to lack of technologies to move the water. c. highly productive and bring cooperation among the traders. d. a problem, since monopolists would come to own too much.