At Teleport data lair, we’re always busy adding new city data for users to compare and rank cities. Just recently, we added LGBT info and data on outdoors. The next addition rolling out will be detailed data on gun ownership and gun related crime.

The number we’d like to show our users is the number of guns owned per 100 residents. Country level data is relatively easily available, but for the US, we would not be providing much value if we just had country level data due to the large variation in ownership between states.

Gun ownership is a sensitive topic, especially in the US, which might explain why it’s difficult to come by total gun ownership data for US states. A few resources online give a stab at coming up with these stats though. One source simply takes the US average guns per person number and multiplies that with the population of each state. This effectively assumes every state has the same ratio of guns to people, which is clearly not true.

Another much publicized source got some paradoxical results—according to them, Wyoming, the state with the most guns per capita, has 20 guns per 100 people. This is impossible to reconcile with the US average of 112 guns per 100 people. In fact, they misinterpreted ATF data on how many firearms were registered within a certain timeframe as total number of firearms. Additionally, the ATF data only keeps track of a subset of types of firearms. Last but not least, private sales are not subject to any registration or background checks at all.

Nevertheless, the data ATF offers, even with its limitations, is one of the few available on state level, so we tried to make most of it. The simple assumption we made was that wherever people register more firearms within a timeframe there are also more firearms in total. The numbers seem to agree quite well with recently published data on “super owners” in the US. Combining this data with numbers on gun related crime, we can create an interesting looking plot.

We’ll leave interpreting the results to the reader.

(The graph is interactive, so feel free to play around with it.)