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An economist has built a map of US drug prices, which he says could help law enforcement identify how it's trafficked from city to city.

The work by an economist at Michigan State University, Siddharth Chandra, generally supports known theories about drug trafficking in the US, but he says it also delivers key new routes not already identified and could be a great tool for investigations.


The study focussed solely on cocaine trafficking, and used statistics publicly available and published by the National Drug Intelligence Centre (NDIC) of the US Department of Justice. As an economist, Chandra focussed solely on cost. All the DOJ data refers to the wholesale prices of powdered cocaine, as gathered by officers during arrests and subsequent interrogations. He looked at data from 112 cities, gathered between 2002 and 2011, and looked for links between 6,126 pairs of cities.

The basic premise is that source cities, where the drugs are coming into the country, will have the lowest wholesale prices. As it moves towards its final destination, the price rises. If there is an unexpected peak in costs at the source, say, because of a shortage, that will make the final end price far higher. It will also show which cities are most dependant on that particular source or route. Using this structure, Chandra analysed the general flow of cocaine through the country, as well as the price structure so that he could identify a location as a "source", "destination", "transit", or "isolate" city.

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The analysis showed, as was expected, that "cities in the south and west have the lowest prices, and there is an upward gradient as one moves from the south and west to the north and east".

Source cities were shown to be located along the southern border and west coast up to Washington state. But Chicago stood out like a sore thumb. Chandra writes in an article published in the


Journal of Drug Issues that data showing Chicago to be a hub suggests "that the cocaine traffic has made inroads into the heart of the Midwest". "There are a variety of reasons that this may be the case, including the city's long history of organised crime and the cultural affinity of segments of the growing Spanish-speaking population with links to Mexico, a factor that has been identified in the context of trans-Atlantic cocaine flows." It's a pretty broad interpretation, but then, Chandra is an economist and is merely presenting the facts -- everything else is theorising and speculation.

City status based on the combination of outward and inward links classification determined by cluster analysis.

Another area joins Chicago in letting down the northern side, "by virtue of their status not conforming to the status of other cities in their neighbourhood", the second-largest city in Connecticut. "Chicago and New Haven, both... appear to have stronger properties of a source city than their neighbours. This suggests that shipments of cocaine arrive in these cities before being dispersed in their respective regions. Therefore, they can be characterised as regional hubs for cocaine trafficking." Atlanta was also shown to be a trafficking hub.

A few key points not already pulled out in route maps developed by the NDIC include Kansas City being identified as having "source-like" properties, making it an important link in the drug-chain, and Jacksonville in Florida and Baltimore in Maryland both exhibiting "transit-like" properties. Newark, Philadelphia and Washington were all previously classed as "unintegrated", but Chandra's report found they had "destination-like" properties, "with more than 20 inferred inward links each". "The reclassification of these cities as destinations would expand the cluster of 'destination' cities in the northeastern United States into a contiguous region to the south."


If we could develop maps like Chandra's in realtime, inputting data on costs as they flow into the law enforcement system, new routes and temporary rerouting cities could be identified and human resources dispersed to battle it accordingly, "As an economist, the big takeaway is that prices carry some valuable information about trafficking in illegal goods," said Chandra. "These data enable us to identify suspected links between cities that may have escaped the attention of drug enforcement authorities. By identifying patterns and locations, drug policy and enforcement agencies could provide valuable assistance to federal, state and local governments in their decisions on where and how to allocate limited law enforcement resources to mitigate the cocaine problem."

The data does not account for drugs coming in by air or water, Chandra concedes, and is totally reliant on those arrested telling the truth to police officers during investigations. It also does not account for those not arrested operating separate networks that affect prices.

Nevertheless, Chandra suggests the model could be used for other drugs being trafficked in the US, which the NDIC holds price information on. This includes heroin, MDMA and methamphetamine.