I think it depends on where you are in your career and what doors are open to you. It's hard for a new, unpublished writer to break into publishing during great economic times, but even harder during a recession. But as Christians, we have to remember that God is still on the throne and He's the same God in the best of times, as well as the worst of times. Several authors and I are a testament, that new, unpublished authors can receive their first contract during a recession. In fact, it seems like more of a miracle.
Pre-published Authors
If you are still unpublished, take advantage of the fact that you can write whatever is on your heart and on a schedule that is convenient for you and your family. One positive aspect about a recession is that it's temporary. The market will change again, and if you are willing to be patient, it will swing back in favor of what you're writing. With God, everything is about timing and occurs in its proper season.
Don't try to write to a market. By the time you finish your book and begin shopping it around to editors, the market will have changed again. This is a time to sharpen your skills and have other books available. If you have plenty of finished manuscripts to sell, a publisher will be more confident in your ability to finish a novel, to write a series, and meet deadlines so you won't be a "one-book wonder". You will have more to offer readers after your first book is contracted.
New Contracted Authors
These authors have a foot in the door, but they don't have a sales history and may not be able to get anything published that would be considered "risky". Writers with new contracts are getting feedback directly from their agent and publishers. They know more about the direction of the market because of this feedback. These authors can talk to their contacts and receive professional input to which most unpublished authors don't have access.
For instance, a publisher gave me a revision letter that would require me to rewrite a significant amount of the manuscript. A month later, the recession hit hard and they stopped buying fiction. My agent, Terry Burns, pulled me off that story and had me lengthening another manuscript for a different editor that showed some interest. This publisher was still buying books in spite of the recession. This wasn't something I would have known without my agent's guidance.
In this case, I'm not exactly writing to a market, but I'm reworking what I've already written to make it more marketable for what is in demand now. However, the reworks aren't a complete rewrite and it isn't changing the heart of my story.
Multi-Published Authors
These authors have a proven sales history, a foot in the door with several publishers, and an agent helping them to manage their career. They can sell books on proposal and may even be asked to write a book for a "risky" sub-genre that a publisher might want to test in the market. Multi-published authors are in a better position to determine if they want to write for the market, write books from their hearts, or a combination of both.
I say this, because their manuscripts are rarely thrown in the slush pile. They are read faster than an unknown author and their stories will be contracted faster as a result. They can catch a trend much quicker than a new author. Many depend on their writing income for a living and write full-time. This means they can finish books faster than an author who is trying to write between a day job, family and church activities.
I believe an author can write both to the market and the books of their heart, especially when they stay true to what God has called them to write. This doesn't mean there won't be down times, but it does mean that you might grow from one season to another. In other words, what you start out writing during the first ten years may evolve into something different through the next ten years.