Guesstimation 2.0: Solving Today’s Problems on the Back of a Napkin
Lawrence Weinstein

I got a review copy of this book, and initially decided I wasn’t going to review it—I hate those sorts of consulting-company-interview estimation problems, you know, like “what percentage of all the shampoo bottles in the world are in an airplane at this moment” or “how much poop does the San Diego Zoo produce per year” or whatever.

But I picked it up in an idle moment and found myself spending far longer reading it than I had intended. Weinstein is clearly a master estimator, and anyone actually interested in estimation will find a wealth of information here. In addition to working out the solutions to many estimation problems, it also includes lots of advice about estimation in general. But what I enjoyed most is his fun writing style and his quirky choice of questions, like “how much fuel would airlines save if they required all passengers to urinate before boarding?” (as, apparently, Nippon Airways began doing in 2009, though I imagine not actually for fuel efficiency reasons), or “how many bullets does it take to cut down a tree?”, or “which has more mass, the air or the brains in a movie theater?” (Answers: not much, about ten thousand, and the air by a factor of ten.) He is also able to leverage physics to estimate answers to lots of interesting questions that would never show up in an interview, because they’re so difficult to get a handle on otherwise, like “how far away can you detect a candle on a clear, dark night?” So even though I probably won’t end up using any of the techniques myself, it ended up being a fun book nonetheless.