Michael Schaffer's book One Nation Under Dog explains the reasons why Americans find devotion to pets essential, according to a review from The Miami Herald .

He wrote that the US$43 billion-per-year US pet market is a dollars-and-cents representation of dog's evolution to a member of the family.

"Attachments to companion animals defy ordinary logic but conform perfectly to emotional logic," Schaffer said. "To talk about that attachment is to create common ground."