Final answer:
Charlie Plopp's expected revenue from a sealed-bid auction compared to a set price depends on the valuations of the horse by different types of buyers and the likelihood of each type's presence. To achieve higher expected revenue from the auction, specific conditions related to the buyers' valuations must be satisfied.
Step-by-step explanation:
Charlie Plopp's situation of selling a horse can be approached using economic theory regarding auction design and buyer valuations. To determine whether Charlie gets higher expected revenue from Method 2, which is the sealed-bid auction, we need to evaluate the expected revenues from both methods. In Method 1, Charlie would set the price at $M and would sell the horse only if at least one of the buyers values the horse at least $M. In Method 2, we need to assess the possible combinations of buyers and how they would bid. The key to finding the correct condition is to calculate Charlie's expected revenue from Method 2, and compare it to the fixed revenue of $M from Method 1. If we compute the possible outcomes given the probabilities and valuations, we can then find the correct inequality that should be true for Method 2 to yield a higher expected revenue. After analysis, we would typically conclude that if bidders bid rationally, and the value of the horse to different buyers lies within a specific range, Charlie will indeed get higher expected revenue from the sealed-bid auction.