The annual marijuana crop harvested in the U.S. is now the nation's most valuable, worth more than cultivation of corn and wheat combined, according to an analysis by the former head of the legalization group NORML.

Reuters reported Dec. 18 that public-policy analyst Jon Gettman estimated the value of the U.S. marijuana crop at $35 billion annually, with California, Tennessee, Kentucky, Hawaii and Washington each producing more than $1 billion worth of the illegal drug each year. Gettman estimated the annual California marijuana crop to be worth $13.8 billion.

The estimates were based on previous federal reports showing that the U.S. produced more than 10,000 metric tons of marijuana each year.  At $1,606 per pound, that makes the crop worth at least $35 billion, compared to $23.3 billion for U.S.-grown corn, $17.6 billion for soybeans, and $7.4 billion for wheat.

"Marijuana has become a pervasive and ineradicable part of the economy of the United States," Gettman said. "The contribution of this market to the nation's gross domestic product is overlooked in the debate over effective control … The focus of public policy should be how to effectively control this market through regulation and taxation in order to achieve immediate and realistic goals, such as reducing teenage access."

A spokesperson for the White House Office of National Drug Control Policy countered that marijuana use is an "inherently harmful activity" that lands more U.S. teens in addiction-treatment programs than all other drugs combined.