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.

They interview a group of scientists who propose radical solutions to extreme weather — floating pontoons to drive warm ocean water down to inhibit the formation of hurricanes, and a giant "garden hose to the sky" to pump sulfur dioxide into the stratosphere to replicate the global-cooling effect of volcanic eruptions.

Here the authors seem to abandon the relative impartiality of their previous chapters. They give the scientists free rein to describe and defend their theories, even though the proposals are radical enough to deserve stronger scrutiny.

Had Levitt and Dubner been a bit more skeptical, the chapter might have served as a foundation to inform readers of the possibilities and given them a chance to reach their own conclusions. Instead readers might feel like they're being preached to.

Certainly the authors have the right to insert their own viewpoints. But the effect is a little disappointing when the previous chapters were written with a more academic perspective.

The authors don't seem to mind criticism. In the introduction they say they'll be disappointed if the book doesn't start some quarrels.

But most of the book will draw interest, not antagonism. "SuperFreakonomics" isn't necessarily super or freaky, but it does make economic analysis a little less dismal.