The 1991 Assessment combined the Technology and Economic Panel, expanded participation of developing country experts, and added two senior advisors who serve on the Panel but not on a Technical Options Committee. The five Technical Options Committees and the Economics Committee reports are the primary basis for this document 1 . Over 240 experts from 38 countries' were members of these committees. Hundreds of additional experts served as advisors to the six committees and as peer reviewers. The Assessment describes current uses and quantities of controlled substances, estimates the technically feasible phaseout dates, estimates the quantity and time period for use of transitional substitutes, and specifically describes the implications of 1997 or earlier phaseouts.