Mapping the Price of Weed
How to study underground economies? One way is to crowdsource data collection.
Floatingsheep gathered user generated data from from the Price of Weed Web site and teased out a visualization of who’s paying what across the United States.
The map above appears in the September issue of Wired under the headline, “Infoporn: O Say, Can You THC?”
The map featured in WIRED is taken from a much more detailed research paper focused on the potential for user-generated data to shed light on underground economies such as marijuana use. The map relies upon thousands of user reports on marijuana purchases referenced to city locations from the Priceofweed website (see our earlier posting). After cleaning the data to get rid of the outliers, we created a continuous surface using a statistical interpolation technique known as kriging to identify the average variance among price differences through a spherical semivariogram model. To obtain a price for each location show in the map above, an interpolated value was estimated as a weighted average of prices from its twelve neighboring points…
…We’re in the process of finalizing a paper analyzing this data including a state and city-level multivariate analysis of price. Key explanatory variables in the models include the legality of medical marijuana, level of production and an intriguing distance decay effect as one moves away from Northern California.
Prices are per ounce.