"A recent sales study indicates that consumption of seafood dishes in Bay City restaurants has increased by 30 percent during the past five years. Yet there are no currently operating city restaurants whose specialty is seafood. Moreover, the majority of

The argument, although presented in a succint way, is not free from faults. The author makes a few erroneous assumptions that lead to these faults. Firstly, the author states himself that seafood consumption has increased in Bay City restaurants by 30 percent. We should note that he is referring to more than one restaurant & not just a specific one. Hence, the sales of possibly a large number of restaurants has gone up & stating that only a specific restaurant must have become profitable as a result of it, sounds inconsistent & illogical.

Another faulty assumption that the author makes is - he assumes that a restaurant must specialize in a variety of food in order to serve it. Since seafood consumption has gone up in the city, it may so be that the inhabitants are consuming increasing amounts of seafood in possibly numerous restaurants throughout the city. In that case, since the customer base is distributed more or less evenly throughout various businesses in the city, it doesn't necessarily follow that the Captain Seafood restaurant has become profitable.

Thirdly, the author fails to take into account the case that the food served at the Captain Seafood restaurant (even though it specializes in seafood) may be inferior in taste or quality or both, to other eateries in Bay City. In such a situation, if customers do not find the food served there to their liking, they might abandon the Captain Seafood restaurant in favor of other restaurants. This situation would still be consistent to the recorded fact that seafood consumption has increased, but wouldn't necessarily mean that the Captain Seafood restaurant has become popular or profitable. The author should have ascertained whether the food served at the Captain Seafood restaurant is actually preferred by the customers over other restaurants before making the declaration that he did in his argument.

A fourth faulty assumption is based on a fact that the author fails to precisely ascertain - the actual level of consumption of seafood after the 30 percent increase. It may happen that five years ago, before the increase occurred, the level of seafood consumption was so low as to be negligible. In such a case, even after a 30 percent increase, the level of consumption may still not be high enough so as to guarantee definite profits for the Captain Seafood restaurant, even if the only contribution to the increase was from sales at the restaurant. The number of customers actually ordering seafood would still be pretty low, low enough that the profits or popularity of the restaurant would not increase by any significant degree at all.

Thus, the author makes a few faulty assumptions & fails to take into account some contradicting scenarios that call into question the accuracy of his argument. If he had noticed these unexplained situations & questions, then his argument might have been more reasonable & acceptable.