In Freakonomics, Steven Levitt attempts to use mainstream micro-economic methods to analyze topics not usually considered part of the body of economics. So the premises of the book are not Austrian.
http://en.wikipedia.org/wiki/Steven_Levitt
The genesis of Freakonomics is the work of another Chicago economist, Gary Becker, who applied mainstream micro-economic methods to topics outside economics proper, such as the family.
http://www.econlib.org/library/Enc/bios/Becker.html
