The US isn’t an outlier for mass shooting death rates, even among European or developed countries.
This study found the mass shooting death rate between 2000-2014 in Finland, Switzerland and Norway was higher than in the US. (1)
Another study looked at public mass shootings between 2009-2015.
Norway, Serbia, France, Macedonia, Albania, Slovakia, Switzerland, Finland, Belgium, and Czech Republic all ranked higher than the US in public mass shooting death rate. The author also found the mass public shooting death rate for all Europe was nearly the same as the US.
.0881 for Europe
.0879 for US
(2)
It’s sometimes claimed that small countries like Norway skew the data. After all, Norway only had 1 mass shooting between 09′ and 15′.
Here’s a better way to think about it.
Norway has 5.2 million people. There are 7 states in the US with between 4.4 and 5.7 million. Over the same time period 3 of them had 0 mass shootings and 4 of them had 1, the same as Norway. All the death totals for these 7 states combined is lower than Norway’s.
So of course the US had more shootings over the sample period, the US has over 62 times as many people as Norway. But if we focus in on states of similar size to Norway, the states did much better.
[1] https://www.scribd.com/document/292008708/Mass-shooting-comparisons-Schildkraut-and-Elsass