Book Review: More Sex is Safer Sex

I just finished reading Steven Landsberg's 2009 book More Sex is Safer Sex. The subtitle is "The Unconventional Wisdom of Economics", which pretty accurately sums up the content. It is unconventional, and uses the tools of economics. At the heart of the book is the premise that problems arise when we don't face all of the costs, or are unable to capture all of the benefits, of our decisions. Landsberg uses that premise to illustrate a number of surprising arguments, such as this from early in the book:

When you're splitting the dinner check, ordering dessert can be a lot like littering - you get the benefits and the costs spill over onto your friends. If the $10 double chocolate mousse is worth only $4 to you, you really shouldn't order it - and you won't, if you're paying your own way. But when you split the check ten ways, that mousse starts to look (to you) like a bargain.

I found a lot of the stories and examples in the book to be deliberately provocative. For instance, Landsberg argues that firefighters should be allowed to keep any property that they save from a burning building (they face all the costs of their actions, so they should be able to claim all of the benefits). Sometimes, provocativeness can be a good thing, but I feel like in much of the book Landsberg is over-playing his hand. And there are clearly cases where, in his zeal for revealing some surprising results, he over-stretches, such as this:

Any act of charity entails a clear moral judgment. When you give $100 to CARE, you assert that CARE is worthier than the Cancer Society. If that's your honest judgment when you give your first $100, it ought to be your honest judgment when you give your second $100. Giving to the Cancer Society tomorrow means admitting you were wrong to give to CARE today.

Of course, it is likely that there is diminishing marginal utility to giving to each charity. That means that each donation you give to a charity provides you with less satisfaction (or happiness) than previous donations you gave to the same charity. So it is by no means a given that if you receive more utility (or satisfaction) from your first $100 being given to CARE, that your second $100 would provide you with more utility if also given to CARE than if you gave it to the Cancer Society. Landsberg does acknowledge this, although not in as many words, and it is buried in the appendix to the book.

Overall, there are some interesting points made in the book, and if you want to see the application of economic costs and benefits to a wide range of (often surprising) situations, this book will provide you with that. I made a number of notes of things that will be helpful in my teaching. However, if you are sceptical about the use of economics, this book probably won't convince you. And to top it off, Landsberg's in-your-face style won't be to everyone's taste.