Steven E. Landsburg - More sex is safer sex: the unconventional wisdom of economics

This is a book about unconventional applications of conventional economics. My first debt is to the many innovative thinkers who devised these applications. Some are named in the chapters and others in the appendix.

I am grateful to the editors of Slate , who for ten years have given me remarkable freedom to write about whatever was on my mind. Some of the arguments in this book first appeared in my Slate column, though mostly in highly abbreviated form. Here Ive taken the opportunity to expand on them considerably.

I am grateful to the thousands of Slate readers who have called me to account on points that needed more explanation, and occasionally on points where I was wrong. Several chapters in this book have been greatly improved by what I learned from my readers.

I am grateful to the members of the daily lunch group who have vetted so many of these ideas and contributed to my general education. Most particularly, I owe thanks to Mark Bils, Gordon Dahl, Uta Schnberg, Alan Stockman, and Michael Wolkoff, all of whose comments and criticisms have improved this book.

I am especially grateful to Mark Bils, from whom Ive stolen so many ideas and insights that he should probably have been called a coauthor.

I am grateful to my brain trust of brilliant noneconomists who have helped me understand what is and isnt obvious, and have helped me find the perfect words to express some difficult ideas. Thanks especially to Diana Carroll, Michael Raymond Feely, Sharon Fenick, Nathan Mehl, Tim Pierce, John Rosevear, Ellen Keyne Seebacher, and Lisa Talpey. Im sure that list is not complete.

I am grateful for the encouragement and assistance of Bruce Nichols at Free Press.

And I am grateful to my parents for being proud of me even though they hate the title. For a lot of other things too, come to think of it.

Common sense tells you that promiscuity spreads AIDS, population growth threatens prosperity, and misers make bad neighbors. I wrote this book to assault your common sense.

My weapons are evidence and logic, especially the logic of economics. Logic is most enlighteningand surely most funwhen it challenges us to see the world in a whole new way. This book is about that kind of logic.

Daughters cause divorce. A thirst for revenge is healthier than a thirst for gold. A ban on elephant hunting is bad news for elephants, and disaster assistance is bad news for the people who receive it. Malicious computer hackers should be executed. The most charitable people support the fewest charities. Writing books is socially irresponsible; elbowing your way to the front of the water-fountain line is not. The tall, the slim, and the beautiful earn higher wagesbut not for the reasons you think.

Each of those statements is closer to the truth than you might imagine. If your common sense tells you otherwise, remember that common sense also tells you the earth is flat.

What youre about to read is a celebration of all that is counter, original, spare, and strange. I mean every word seriously and every word in fun. These are carefully considered arguments about important issues. But theyre also surprising arguments, and surprises are fun. This book will give you new insights about how the world works. Sometimes it might outrage you. I hope it also makes you smile.

Come out to my suburban neighborhood on any crisp October Saturday, and I will show you a minor tragedy: on every lawn a man with a leaf blower, blowing his leaves onto the next mans lawn. Eventually, they all go inside to recover from a hard and thoroughly unproductive mornings work.

Thats a bad way to spend a Saturday. If we all ditched our leaf blowers and stayed inside to watch football, wed all be happier. Unfortunately, human beings are too rational for that. Blowing leaves always makes sense, whatever your neighbors do. If everyone else blows leaves, youd better blow them also to avoid a double cover. Or, if everyone agrees not to blow leaves, your best strategy is to cheat and have the only clean lawn in the neighborhood.

Economics is largely about the surprising and sometimes tragic consequences of rational behavior. When theres an exciting moment at the ballpark, everybody stands up trying to see better, and therefore nobody succeeds. At parties with a lot of simultaneous conversations, everyone speaks loudly to be heard over everyone else, and everyone goes home with a sore throat. Still, its rational to stand at the ballpark, and to yell at the party. We stand and we yell for the same reason we blow leavesfrom exquisite (and entirely rational) concern for our own interests and none for the harm that spills over onto our neighbors.

Its a general principle of economics that things tend to work out best when people have to live with the consequences of their own behavior , or, to put it another way, things tend to work out poorly when the consequences of our actions spill over onto other people . Simple and obvious as that general principle might sound, it has the power to undermine vast deposits of conventional wisdom. It suggests that the world has too few people, too few misers, and not enough casual sex, but just the right amounts of secondhand smoke and child labor. It implies that a thirst for gold is socially ruinous, but a taste for revenge can be a social godsend. It casts light on why the tall, the thin, and the beautiful earn higher wages. It suggests sweeping reforms of the legal system, the political system, the tax code, and the rule against jumping to the front of the water-fountain line. And it explains why automobile insurance in Philadelphia is so damn expensive.

More mundanely, it tells us theres too much litter on the streets. Thats less obvious than you might suppose. Sure, theres a lot of litter, but a lot isnt always the same as too much. After all, some litter ought to be there because the alternatives are worse. That half-eaten sandwich you just stepped on? Maybe someone dropped it to avoid being stung by a hornet. The newspaper wrapped around your ankles? Maybe the wind took it while someone chased down the tax returns that had just fallen out of his briefcase. And if you have a heart attack while youre walking down the street with a Popsicle, nobody thinks you should make a beeline for the nearest trash receptacle before collapsing to the ground.