This may not directly answer your question, but I feel it's relevant. Even during a bad economy, people buy books. They are just more selective about what they buy. It's a similar thing with libraries. My local library tends to get books from well-known writers before drawing on the more obscure ones. The one thing a writer can do is promote his or her book. It doesn't always guarantee good sales, but it's better than nothing.
Books are an inexpensive entertainment, especially for people who suddenly have a great deal of time on their hands. Even the cinemas have done well during the recession, and that is a somewhat more expensive form of entertainment than books.
:O Cinema is cheaper than books in the USA? Wow, jealous.... Here, the average new hardback (for instance the new Dan Brown book) retails for about $65...new large format books retail at about $40-$45, and your standard paperback novel is about $30. You would be lucky to get more than two decent books for under $50. Movie tickets by comparison are about $16 for an adult.
Oops. wrong order...but the rest of my post has it the right way around...books cheaper than cinemas = reason to leave NZ and go to America...
it's only common sense... when life gets tough, even the tough need a break from reality, which is why fiction and film flourished during the great depression and will keep on doing so... the worse things get, the more people need to escape into fiction and fantasy... and their rage finds an outlet in all that icky violent stuff...