The primary incentive for economic agents to formulate expectations rationally is to

Economists love auctions because

a. They maximize consumer surplus b. They create efficiency by allotting the item to the highest-value bidder c. They create efficiency by allotting the item to the lowest value bidder d. All of the above

As more bananas are consumed, marginal utility decreases at

a. the same rate for all people, approaching but never reaching zero b. the same rate for all people, and eventually becomes negative c. different rates for different people, and for everyone, it approaches but never reaches zero d. different rates for different people, and eventually, for everyone, it becomes negative e. different rates for different people, and eventually reaches zero where it remains (it cannot be negative)