A few readers have asked for more thoughts on the financial impact of taking a writing sabbatical.
First of all, understand that money is extremely important--even to writers. For those of you who disagree, I recommend reading A Room of One's Own by Virginia Woolf. The blindingly obvious truth: you will need to save enough money in advance to pay all your expenses during any unpaid sabbatical leave.
If your response to this is a pathetic excuse like I don't have that much money, then you are not a writer. You are an excuse-maker.
Start saving. Save six, eight or twelve months' worth of expenses. Better yet, save even more, just in case you get too used to not working.
If your response is I can't save that much money, then once again you are not a writer. No one should take you seriously.
If you truly see yourself as a writer, then you should already understand the idea of simplifying your life to create time to write. Many of the activities that distract us from our writing (e.g., cable TV, shopping, buying and accumulating stuff) cost money, so cutting them out of your life has a dual benefit--it enables you to write more and it enables you to save more. (PS: feel free to substitute any activity that's important to you in place of the word "writing.")
Money is a tool. It empowers writers.
And your goal to save money so you can afford a sabbatical is just as important as what you write during it.