During his 52-year career in marketing and opinion research, Humphrey has had overall responsibility for more than 8,000 surveys in over 80 countries, for governments, corporations, and foundations and other non-profits. He has been invited to the White House ten times under seven administrations and has testified more than ten times to Congressional Committees and Subcommittees on Social Security, health care cost containment, Medicare, aging, policies affecting people with disabilities, drug exports, the taxation of employee benefits, and privacy.