Here is a skeptical reply to Baumeister on willpower:
This idea has a visceral, compelling feel to it - it does feel like I'm tired and drained after making decisions - and the idea has received a tremendous amount of attention from scientific and lay communities alike, perhaps partially explaining the duo of scientist/journalist on the dust jacket.
There are a number of problems with the model, and in this post, I'll talk about one of them: the model has been falsified a number of times, including by research performed in the lab of the proponents of the model.
Note that one's perception of cognitive resource depletion matters.
For those interested, that blog post has two follow-up posts which criticize the part of the theory claiming that the resource depleted during ego-depletion is glucose: Glucose Is Not Willpower Fuel and Should You Consume Sugar to Improve Your Self-Control?.
With all that, ego-depletion theory really looks well beyond shaky. The author of these posts also claims we still have no actual working theory of fatigue.
I recently read this book. I've tried to summarize the main points below -- you can read my notes here (MSWord doc). You might also find Derek Sivers' notes useful, which can be found here.
NOTE: The general model of willpower (as a finite resource consumed with use) used in this book does not seem to represent a scientific consensus -- see the comments for more detail.
General Claims
Willpower Depletion
Restoring Willpower
Miscellaneous
I declare Crocker's Rules.
[i] I didn’t see enough evidence to conclude whether the cravings are actually stronger, or people are simply less able to resist them, or both. The book claims that both are true.
[ii] The book seems to imply this mental nagging costs willpower, but I don’t recall it being explicitly stated. GTD is also mentioned, and the lack of Next Actions which one has the materials to execute being included in plans causing people to procrastinate. (p. 79)
[iii] The relevant experiment was conducted in a laboratory, so there is no possibility of the experimental results being affected by the fact that people with more self-control may keep their house cleaner. Self-control was measured in ways like being willing/unwilling to week for a larger sum of money instead of receiving a smaller sum immediately, and choosing healthier foods over sugary snacks.
[iv] I wonder if this means that people are more likely to ignore opportunity costs.
[v] ‘Conserving willpower’ is also mentioned around here, which seemed to imply that effective precommitment helped reduce the willpower costs of overcoming constant temptation by making the decision easier.