OP here. Thanks for the responses. It is in a moderately desirable neighborhood with a good elementary school. The sellers' listing behavior makes me think they're not serious sellers. The house is attractive enough that someone must have made an offer, just not high enough to cover what they paid for it plus commission. I am starting to think that our agent is simply not aggressive enough to write a low offer.
get a new agent. In addition to the other things people have mentioned, your agent should know the trends in the type of market that this house is in in this area. Its not just the area but the type of house within an area.