Economists, and economics writers, spend a lot of time complaining that no one respects what they do. “I don’t tell my doctor how to do surgery,” one young professor told me, “so how come he thinks he can do my job?” All agree that ordinary people don’t understand economic thinking, which often takes blindingly obvious propositions – if you raise the price of something, people buy less of it – and combines them to get unexpected results. Because those results cut across people’s intuitions, they are all too easily discounted, along with the profession that produced them.

Steven Levitt and Stephen Dubner’s new book, “Freakonomics” (William Morrow, 256 pages, $25.95), may change all that. Mr Levitt is the most recent recipient of the John Bates Clark Medal, an award for young economists that’s more exclusive than the Nobel Prize. A professor at the University of Chicago, he is known for the novel questions he asks and the innovative ways he finds answers. His collaborator, a New York journalist with a flair for economics, has performed the tricky feat of translating Mr Levitt’s unusual insights into everyday language without losing the precision of economic thought.

Nowhere in the book will you find dry discussions of total factor productivity or international trade flows; the book covers the sort of “relevant” questions you might see on the cover of Newsweek. Does your real-estate agent really get the best price for your house? How do parents affect the way their children grow up? Is your child’s teacher cheating on high-stakes tests?

The prose is lively, but the explanations have academic rigor. Instead of throwing statistics at you, interspersed with brief quotes from experts who tell you what they believe but not why they believe it, the book shows you the data and walks you through the process of analyzing it.

In the section on cheating teachers, for instance, you’re shown the score reports and invited to find the frauds. I guessed wrong, but when Mr. Levitt disclosed how he’d identified them, it was so clear I could have smacked myself in the forehead for missing it. That is what great economics is – something you wish you’d thought of, because in hindsight it’s obvious. Mr. Levitt thinks of it first.

This penchant for thinking outside the box has made Mr. Levitt a controversial figure. A few years ago he authored a paper that made headlines for suggesting that legalized abortion might have substantially contributed to falling crime rates in the 1990s. Predictably, pro-life activists attacked it, while others wondered if this vindicated abortion as a positive good.

Few made a convincing attempt to examine the paper on its technical merits, and this book offers the lay reader a welcome opportunity to carefully examine the reasoning – including the various tests Mr. Levitt employed see whether this was a freak coincidence or a real effect. Once you’ve gone through the problem step-by-step with Messrs. Dubner and Levitt, it’s hard to disagree with their conclusion.

Many economists give into the temptation to pretend that economics has provided a “scientific” resolution to some essentially philosophical question, such as the correct level of taxation. Mr. Levitt, to his credit, is at pains to point out that the study doesn’t prove that legalized abortion is a good thing:

There are roughly 1.5 million abortions in the United States every year. For a person who believes that 1 newborn is worth 100 fetuses, those 1.5 million abortions would translate … into the equivalent of a loss of 15,000 human lives. Fifteen thousand lives: that happens to be about the same number of people who die in homicides in the United States every year. And it is far more than the number of homicides eliminated each year due to legalized abortion. So even for someone who considers a fetus to be worth only one one-hundredth of a human being, the trade-off between higher abortion and lower crime is, by an economist’s reckoning, terribly inefficient.

The section on abortion and crime embodies all the best things about the book. It lets a reader approach a problem the way an economist does. Better still, it lets him see how wrong his intuitions can be. Both opponents and proponents of Mr. Levitt’s original paper assumed that if it were correct, that would mean that more abortions were a good thing. This idea is unraveled in the passage above with a simple calculation that anyone could do.

I’m sure opponents of legalized abortion who responded with moral outrage instead of quantitative analysis will be slapping themselves on the forehead, wondering how they could have missed something so obvious. I know my forehead’s getting sore.

Ms. McArdle last wrote in these pages on deregulation.