Scary story from today’s Denver Post:

Nearly one-third of the crimes committed in Denver occur within 1,000 feet of a medical marijuana dispensary, according to new statistics provided by the city Wednesday.

Yikes! Sounds like those pot clinics are a cause of crime in Denver. Are they? Let’s look at some basic math:

• Number of medical marijuana clinics in Denver, as of 2010: 390.
• Total area of 1,000-foot radii circles around all 390 clinics (remember Ï€•r^2?): 1.23 billion square feet.
• Total area of Denver: 4.32 billion square feet.
• Proportion of Denver’s area that is within 1,000 feet of a medical marijuana clinic: 0.28, or nearly one-third.

In other words, the proportion of crimes committed near Denver marijuana dispensaries happens to be the same as the proportion of the city that exists near Denver marijuana dispensaries.

Now, okay, this little analysis ignores a few things. There are probably more clinics today than there were in 2010, some of the 1,000-foot radii probably overlap due to the proximity of clinics to each other, etc. But still, a little math might remind us that’s there’s not much of a story here.

[Cross-posted at Mischiefs of Faction]