U.S. DEPARTMENT OF STATE
INTERNATIONAL NARCOTICS CONTROL STRATEGY REPORT, MARCH 1996

United States Department of State

Bureau for International Narcotics and Law Enforcement Affairs

EXECUTIVE SUMMARY

Methodology For Estimating Illegal Drug Production

Since much information is lacking on yields, the numbers are subject to revision as more data become known. The nature of the illegal drug trade, in which the traffickers take great pains to maintain the security of their activities, makes it difficult to develop precise information. This is particularly relevant given the tremendous geographic areas that must be covered, and the difficulty of collecting reliable information in diverse and treacherous terrain.

What We Know with Reasonable Certainty. The most reliable information we have on illicit drugs is how many hectares are under cultivation. For more than a decade and a half, the USG has estimated the extent of illicit cultivation in a dozen nations using proven methods similar to those used to estimate the size of licit crops at home and abroad. We can thus estimate the area under cultivation with reasonable accuracy.

What we know with less certainty. Where crop yields are concerned, the picture is less clear. How much of a finished product a given area will produce is difficult to estimate, since small changes in such factors as soil fertility, weather, farming techniques, and disease can produce widely varying results from year to year and place to place. In addition, most illicit drug crop areas are inaccessible to the USG, making scientific information difficult to obtain. Moreover, we must stress that even as we refine our methods of analysis, we are estimating potential crop available for harvest.

Not all of these estimates not allow for losses, which could represent up to a third or more of a crop in some areas for some harvests. Thus the estimate of the potential crop is useful in providing a theoretical, comparative analysis from year to year, but the actual quantity of final product remains elusive.

Since cocaine has been at the top of the USG's drug-control priority list, the USG has been trying to develop better yield data. USG confidence in coca leaf yield estimates has risen in the past few years, based upon the results of field studies conducted in Latin America. Four years ago, after completing preliminary research, the USG for the first time began to make its own estimate of dry coca leaf yields for Bolivia and Peru instead of relying solely on reports from the governments of those countries. Additional research and field studies have helped refine these estimates and make similar improvements possible in estimates of other drug crops. In all cases, multiplying average yields times available hectarage indicates only the potential, not the actual final drug crop available for harvest.

Harvest Estimates. Estimating the quantities of coca leaf, opium gum, and cannabis actually harvested and available for processing into finished narcotics remains a major challenge. While we are making progress, at this time we cannot accurately estimate this amount with precision for any illicit crop in any nation.

While farmers naturally have strong incentives to maximize their harvests of what is almost always their most profitable cash crop, the harvest depends upon the efficiency of farming practices and the wastage caused by poor practices or difficult weather conditions during and after harvest. Up to a third or more of a crop may be lost in some areas during harvests.

In addition, mature coca (three to six years old), is more productive than immature or aging coca. Variations such as these can dramatically affect potential yield and production. Furthermore, if we continue to see limitations in the expansion of new coca we may begin to see dramatic declines in the next few years in productivity of existing fields. Factors such as this will produce fluctuations in estimates.

Additional information and analysis may enable us to make adjustments for these factors in the future. Similar deductions for local consumption of unprocessed coca leaf and opium may be possible as well through the accumulation of additional information and research.

Processing Estimates. The wide variation in processing efficiency achieved by traffickers complicates the task of estimating the quantity of cocaine or heroin that could be refined from a crop. These variations occur because of differences in the origin and quality of the raw material used, the technical processing method employed, the size and sophistication of laboratories, the skill and experience of local workers and chemists, and decisions made in response to enforcement pressures. (See Yield Estimates below.)

The actual amount of dry coca leaf or opium converted into a final product during any time period remains unknown, given the possible losses noted earlier. There are indications, however, that cocaine processing efficiencies may not be as high as previously supposed, leaving traffickers with considerable room for improvement. Nevertheless, increasing seizure rates can affect the future profitability of the industry, and raise the cost of doing business.

Figures Will Change as Techniques and Data Quality Improve. Are this year's figures definitive? Almost certainly not. Additional research will produce revisions to USG estimates of potential drug production. This is typical of annualized figures for most other areas of statistical tracking--whether it be the size of the US wheat crop, population figures, or the unemployment rate--that must be revised year to year. For the present, however, these statistics represent the state of the art. As new information becomes available and as the art improves, so will the precision of the estimates.