Pop Quiz: What's New About 'Freakonomics'?

In the economy-makes-strange-bedfellows category, it's hard to beat the calculations of Steven Levitt and Stephen Dubner, authors of the 2005 best-seller, "Freakonomics." The book applied economic theory — not moral standards — to societal issues like effective parenting and why people cheat. It not only led to some pretty controversial findings — like the suggestion that a drop in crime in the United States could be related to abortion laws — it made media stars of Levitt and Dubner.

Now comes volume II, "SuperFreakonomics," and it looks like Levitt and Dubner are up to even more headline-grabbing tricks. In "SuperFreakonomics," the authors, (Levitt is an economist at the University of Chicago; Dubner is a journalist), go straight for hot-button issues. Out: studies of names and children. In: terrorism and global warming. Why global warming? Dubner says the subject was a “natural” given the amount of attention it's getting and because it "includes so much economic and scientific territory," he says.

Yet topicality alone isn't going to sell books, says Cathy Langer, the lead buyer for Tattered Cover, an independent book store in Denver. Though economics books have been doing well for her, Langer was fairly conservative when ordering "SuperFreakonomics." That's because sequels don't always follow originals in popularity, she says.

Just how far into the news cycle have Levitt and Dubner's interests shifted? We checked out the indexes of volumes one and two to find out. Here's a look, as measured by number of subtopics.

Top 5 Topics in "SuperFreakonomics"
1) Prostitution - 37
2) Climate, Global Warming/Cooling - 27
3) Altruism - 16
4) Terrorists, Terrorism - 15
5) Women – 13
(Tie - Doctors, health care and hospitals garnered another 13 mentions between the three.)

Top 5 Topics in "Freakonomics" 
1) Crime, Crime Reduction - 28
2) Incentives - 22
3) Children - 22
4) Names - 18
5) Drugs, Drug Dealers - 14