Writing novels is hard, and requires vast, unbroken slabs of time. Four quiet hours is a resource that I can put to good use. Two slabs of time, each two hours long, might add up to the same four hours, but are not nearly as productive as an unbroken four. If I know that I am going to be interrupted, I can't concentrate, and if I suspect that I might be interrupted, I can't do anything at all. Likewise, several consecutive days with four-hour time-slabs in them give me a stretch of time in which I can write a decent book chapter, but the same number of hours spread out across a few weeks, with interruptions in between them, are nearly useless.
The productivity equation is a non-linear one, in other words. This accounts for why I am a bad correspondent and why I very rarely accept speaking engagements. If I organize my life in such a way that I get lots of long, consecutive, uninterrupted time-chunks, I can write novels. But as those chunks get separated and fragmented, my productivity as a novelist drops spectacularly. What replaces it? Instead of a novel that will be around for a long time, and that will, with luck, be read by many people, there is a bunch of e-mail messages that I have sent out to individual persons, and a few speeches given at various conferences.thanks Apophenia