Summary: In May 1999, the U.S. Department of Agriculture received a petition with about 19,000 signatures requesting a vote on whether to continue the pork promotion program. Fifteen percent of those eligible are needed to require the Secretary of Agriculture to hold a referendum. GAO found that the Agricultural Marketing Service's (AMS) process to validate the pork petition was flawed in three areas: (1) AMS did not accurately estimate the population of pork producers; (2) AMS did not develop a reliable database of petitioner information as a basis for verifying petitioners' eligibility to sign a petition; and (3) AMS used a flawed survey methodology. The Secretary ordered a referendum because he concluded that it was impossible to ascertain the valid petitioners and efforts to revalidate the petition would not result in any greater certainty. He also believed that pork producers should vote on whether to continue the program because the industry had changed dramatically since the last vote in 1988. GAO recommends that AMS strengthen its validation process and seek reimbursement from program funds to pay all referendum expenses.