Trapping requires time, hard work, and money but can be very efficient. Trapping has become expensive for the trapper, and in modern times it has become controversial. In part to address these concerns, in 1996, the Association of Fish and Wildlife Agencies, an organization made up of U.S. state and federal fish and wildlife agency professionals, began testing traps and compiling recommendations "to improve and modernize the technology of trapping through scientific research" known as Best Management Practices. As of February 2013, twenty best management practice recommendations have been published, covering nineteen species of common furbearers across North America.