Can income earning authors take a break? The short answer is "no." The longer answer is "it depends." The more you earn, and can thus save, the longer you can take a break between books.
It also depends on whether you used income from well-earning books to buy items (such as houses or cars) that require regular (high) payments.More expenses, higher earning threshhold required.
I make enough to pay many of my normal expenses. I'm fortunate, but I do work hard.
To reaffirm this premise, I recently downloaded sales and income data from Amazon and Smashwords (an aggregator that handles sales of most of my books for ibooks and Nook).
I learned several things.
1) I do need to publish consistently or income drops quickly.
2) If I lower the price or give away the last book in a series before issuing the new one, sales of the new one are highter.
3) If I give away books on Amazon via Kindle Unlimited, it makes little difference in sales.
4) If I give away non-KU books on Amazon because of a price match with other sites, it not only helps sales but I get a lot of Amazon reviews.
5) If I keep the first box set of a series free on all sites but Amazon (via Smashwords), succeeding box set sales are very good. The moral here, for me, is to leave the first books free all the time. (The next two box sets are always in the top ten of box set sales, and have been number one or two at times. Other authors' sets come and go. My Jolie Gentil series stays high.)
6) Better to write some every day rather than try to crunch out three books at the end of the year. That's kind of a big 'duh,' but worth noting.
It's a good idea to pull historical data every year. You can obsess by examining data weekly or monthly, and it works better if you use that time to write.
* * *