Over the past decade, worldwide production of illicit drugs has risen dramatically: opium and marijuana production has roughly doubled and coca production tripled. Street prices of cocaine and heroin have fallen significantly in the past 20 years, reflecting increased availability. Despite apparent national political resolve to deal with the drug problem, inherent contradictions regularly appear between U.S. anti-drug policy and other national policy goals and concerns. The mix of competing domestic and international pressures and priorities has produced an ongoing series of disputes within and between the legislative and executive branches concerning U.S. international drug policy. One contentious issue has been the Congressionally-mandated certification process, an instrument designed to induce specified drug-exporting countries to prioritize or pay more attention to the fight against narcotics businesses.