The authors of the book "Freakonomics: A Rogue Economist Explores the Hidden Side of Everything" didn't intend to write a New York Times best-seller.

"It was surprising," co-author Stephen Dubner said of the success of his and co-author Steven Levitt's book.

"It was a chance to write the kind of book we both wanted to read. It's a way of looking at the world that we both think is interesting," Dubner said.

That way, which Dubner refers to as "freakonomics," is an application of economics as a "tool kit" for examining all sorts of human behavior, he said.

The authors look at scenarios that seemingly have little to do with each other, and use the economic theory of incentives and research data to explain a trend that can be found within the scenario. In one example, the trend of white-collar crime is compared to the honesty of people who are trusted to deposit money in an unmonitored box for bagels in the office.

Dubner compares the idea of examining the field of economics in "Freakonomics" to the mainstream transition the field of psychology has experienced.

"One hundred years ago, it was this arcane pursuit; now, people talk in psychological terms all the time," he said.

He said that while the book describes a way of thinking and seeing a methodology behind economics, there is "no real purpose" to it.

"We're leery of being seen as having something important to say, as far as advice or prescriptives," Dubner said.

Dubner brought his theories to the Wharton Center's Great Hall on Thursday, where he further expounded upon the ideas in the book and spoke about new research topics the duo is exploring, as part of "World View — The Lecture Series." These may appear in a sequel which will come out in four or five years, he said.

To illustrate their theories, the authors tackle subjects varying from the economy of a crack gang to psychologists that are teaching monkeys how to use money.

Some of the book's examples were based on Levitt's previous research and some were proposed to the authors. Dubner said they will get e-mails from people who suggest areas they should research, or will find people who have done research but don't know how to analyze it.

The men found an "in" with a sociology student who was living with a crack gang to examine how they lived; the student was given the group's notebooks which kept meticulous records of their every monetary exchange. The student said he didn't have any use for them and offered them to the authors, which was gold for them.

"We're willing and able to find data, we work long and hard with data," Dubner said. "There's nothing magical about it."

"It's a good opportunity to upend conventional wisdom and write about the hurly-burly way of the world."