"SuperFreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance" (William Morrow, 320 pages. $29.99) by Steven D. Levitt and Stephen J. Dubner: In their 2005 book "Freakonomics," economist Steven D. Levitt and journalist Stephen J. Dubner used dozens of interesting anecdotes to prove a simple point: "People respond to incentives."

The authors apparently are no exception. After the book sold more than 4 million copies, the pair doubtless realized how lucrative a follow-up book would be.

So they followed the same model for "SuperFreakonomics." It works just as well the second time around.

Their strategy is simple _ crunch numbers about mundane topics to reveal interesting, unexpected conclusions. That's how we get answers to questions we never thought to ask.

It turns out, for example, that prostitutes tend to make more money when they have pimps. Muslim women who observe the one-month fast of Ramadan early in their pregnancy are more likely to have children with certain cognitive disabilities. Some people who are rushed to emergency rooms might have been better off if they just stayed home.

The real point is to make the science of economics a little more fun _ if you learn how to ask the right questions, numbers can give intriguing answers.

The topics are often random and mashed together in a series of tangentially related vignettes. But the writing is deft and seamless enough to keep "SuperFreakonomics" entertaining.

For most readers, the book will be a series of interesting facts that will provide plenty of water-cooler fodder but not much else. The deeper message is for politicians and other decision-makers.

Plenty of decisions get made based on emotion or common sense, the authors say, but that's not always helpful when the numbers tell a different story.

For example, chemotherapy is brutal, expensive and only marginally effective. Yet Levitt and Dubner say doctors keep prescribing it because they have an incentive to offer their patients every option, and lawmakers continue to fund its research because they have an incentive to look tough on cancer.

The situation won't change until and unless the incentives change, they say. It's not a groundbreaking point, but it's made in clear and simple terms.

For the most part, the authors come across as folks who would make for great conversation at a cocktail party. But that changes in a later chapter when they discuss the environment. Continued...