Do you and your colleagues seek something specific in a novel, whether it be a contemporary trend, or something of social relevance such as revolution, war, ethnic struggle, social injustice, etc.? Do you feel that a character-based story is not enough without some larger scale conflict going on, at least in the background? I have noticed that the lit journals are geared for character, but must have some major conflict or a setting of Kuala Lamphur included or be fairly off-the-wall in their short story collections, and it looks like a novel would need something both relative and exotic to be considered these days. And, Nicole Richie aside, stellar writing would be a given.
This is a toughie because I've been writing rejection letters for novels this weekend. One of the things I've said to people is "there's just not enough here". Now, that can be taken in a variety of ways but mostly it means the story wasn't enough to hold my interest for the full novel. Does that mean they have to add a subplot about the conflict in Darfur? No. It means they have to come up with more. What they come up with can be their choice.
However, I have noticed recently that long standing character series such as Nevada Barr's Anna Pigeon books and Donna Leon's Venice series DO tend to involve topical matters. But more important, it's the secondary characters who tend to change or have an epiphany. Anna Pigeon is always our stalwart heroine, but the secondary characters in HARD TRUTH are the ones who have to make huge changes in their lives. It's about the people though, not the situation. Yes the people are involved in polygamy but it's the characters we care about.
I'm a strong believer in characters carrying novels. Even thrillers. When you get a novel that's "about Darfur" you tend to get political polemics. Miss Snark lives in New York City and daily life is political enough, she doesn't want to read about it after hours in the bubble bath car on the train.
I think the thing that's missing in most of the novels I reject is that the characters don't seem to grow or change enough. I read a lot of mystery and thriller submissions and it's like dead bodies are leaves on the ground: no impact. Even in cozies, there has to be some sense that this isn't quite normal and will mean something to the characters.
So, no I don't think there has to be social relevance. I think there has to be emotional resonance. How that is achieved can vary, but I think that's the key.