The DEA does not have a good track record in estimating the size of marijuana crops. "Tip of the iceberg" anecdotes are common, suggesting that any estimate offered by the DEA be increased several fold.

The DEA method for estimating domestic marijuana production was first stated in 1983.

"Using a relatively accurate plant count and conservative weight per plant factors, it is estimated that 1653 metric tons of marketable marihuana were eradicated. The strategic intelligence estimate for 1981 domestic marihuana production was 1200 metric tons. Therefore, the program shows that in 1982, 38% more domestic marihuana was eradicated than was previously believed to exist. Although a total U.S. marihuana production figure is not easily determined, the statistics obtained from this program reveal, without doubt, that the United States is becoming a major source for the drug."(144)

They also explicitly listed the plant yield criteria they attributed to current cultivation.

"To arrive at an estimated weight of marketable marihuana for that which was eradicated, the following factors are used: One sinsemilla plant yields two pounds of marketable material; one regular marihuana plant yields one pound of marihuana. These factors are considered conservative."(145)

The DEA regularly prints a disclaimer in its reports suggesting that such estimating was only acceptable when the DEA itself engages in it. "It should be noted that the total figure of sightings in this report by no means represents the total number of plots under cultivation in the united States and no attempt should be made to correlate the two." (146) A revised comment shows up in every subsequent report.

However, consider this:

"In 1989, 5, 605,460 marijuana plants weighing approximately 2,548 metric tons (MT), were eradicated. DEA estimates that 50% of the domestic marijuana is being eradicated. This would indicate that approximately 5,096 MT of marijuana was cultivated in the United States in 1989."(147)

This is making a correlation between the number of plants seized and the total number of plants grown in the United States.

Furthermore, the statement is just wrong. In every other context except this specific report, the DEA domestic estimate in expressed as a net figure, what was not seized. In this context, they present the figure as a gross figure. This incorrectly minimizes the size of the market in comparison to other years. The NNICC report for 1989 tactfully ignores this slight of hand, and publishes a net figure of 5000 to 6000 metric tons.(148) This indicates that they hold that roughly 8000 metric tons were grown, the DEA eradicated 2500 MT, and 5500 MT was harvested. This places the DEA's seizure percentage at about 30% of the crop, not the 50% they claim in their own report. Perhaps they made a mistake, and it is only a coincidence that it is so self-serving.

A recent report by a DEA agent in California calculates the value of cannabis in California assuming that they only seize 10% of the actual crop.(149)

The DEA's ability to seize a large percentage of the marijuana grown in the U.S. was called into question above. Their estimates of U.S. production are called into question here.

In the mid 1980's the DEA maintained that U.S. production was only 12% of the country's consumption.

"Anecdotal evidence suggests that the 12% estimate may be low. Projections made by a senior U.S. Forest Service official indicate that domestic production could be about 50% of U.S. supply. In addition, the Oregon Deputy Attorney General, in testimony before the House Select Committee on Narcotics Abuse and Control, stated that the correct figure "may be as high as 50%." During the interviews conducted. . .officials offered estimates ranging from 30% to 60%. It is important to emphasize that these high estimates are impressions rather than conclusions based on firm data."(150)

When the DEA estimated that domestic cultivation provided 12% of U.S. consumption in 1984, they estimated production at 2100 metric tons. In 1984 the Mexican police raided five separate large scale growing sites in Mexico belonging to a consortium reputedly led by Caro Quintero. They seized over 2000 metric tons of marijuana, "(8) times more marijuana than Mexican and American authorities at the time believed was produced annually throughout Mexico."(151)

Regardless of the historical accuracy of DEA's estimates, there is no dispute today that domestically grown marijuana represents tens of billions of dollars of economic activity. "At minimum, this business is worth $20 billion to $30 billion a year," says John Sutton, chief of DEA's cannabis investigations branch (KY.(152) The DEA has estimated that domestic growers have harvested 10 million pounds annually since 1988. Their data, without corrections, would place the 1992 crop value at $26.8 billion.