Is it advisable to admit in cover letters to publishers/agents that one is completing postgraduate studies in writing (in my case, a PhD in Philosophy, writing a novel and exegesis)? Does this suggest a degree of dedication to the craft, or scream 'run for the hills'? Published and highly successful Australian writers have said (at least, privately) that a PhD is strongly advisable to ensure continuity of income from teaching — to supplement the money coming in from publishing. Yet I’ve heard from the publishing industry in the past that academia tends to produce uncommercial/unsellable writing. With more and more post-grad writing pupils winning big literary prizes, is this still the general feeling?
I can't imagine why anyone would think that postgraduate study is a bad thing - whether we like your novel or not is, of course, a different matter. But it would be a pretty bad state of affairs if you were to spend all that time working on your PhD and then feel you have to hide it! There are two separate issues here, though: the PhD and what is produced from it. The PhD will teach you patience and discipline to write a novel (as it takes years), and you shouldn't leave it off your CV. If, however, what you produce from it is uncommercial and unsellable, that's not the fault of your higher education. Certainly, PhDs don't usually produce cracker crime novels, but why shouldn't they? I don't know enough about PhDs in writing, but surely the idea of one (or part of the idea of one) is to produce writing that people - even just your supervisor - want to read.
As research is involved in completing the PhD, perhaps some of that research should look at bookbuyers. Lots of readers shy away from literary fiction because it's not telling them a story they want to read or they feel it's too much hard work. Lots of them flock towards 'commercial' fiction because it's entertaining, and they don't mind being made to think about serious stuff so long as it's easy to read. And creating writing that 'easy to read' is actually extremely difficult - just like writing a catchy pop song is harder than it looks. A PhD that produces a novel that can be entertaining while simultaneously addressing the issues the writer wants to address would take some skill but probably be a great read. Jodi Picoult does this sort of thing on an annual basis.