Earlier this year the Southern Poverty Law Center created a map showing the concentration of hate groups in the US. I adjusted the number of groups in each state by the population in each state showing a different picture. Just after the election the FBI issued a new report that hate crimes in the US have increased in 2015. I thought I would take a look at any possible association between hate crimes, hate groups, and Trump's percentage of the vote.
The graph above shows the linear association between hate groups and hate crimes (both adjusted for population in groups or crimes per million) . There is a statistically significant relationship with 25.8% of the variability accounted for. The regression line suggests that for every increase of one hate group per million there is an increase of hate crimes by 2.41 incidents per million. The District of Columbia has an extremely high rate of both hate groups (26.78 groups/million) and hate crimes (96.69 incidents per million). Massachusetts has the second highest rate of hate crimes (60.49 incidents/million) but a low rate of hate groups.
I looked at the relationship first with DC removed (the relationship became negative and non significant) then with DC and MA removed (little changed). The relationship without these two states is shown below.
I also looked at the association between hate crimes, hate groups, and Trump’s % of the vote in each state. The association between hate crimes and Trump’s % of the vote is confounded by DC and MA having high rates of reported hate crimes and low % of the vote for Trump. Trump had 4% of the vote in DC. With DC removed there is a positive relationship between hate group concentration and Trump’s % of the vote. There is a negative relationship between the concentration of hate groups and Trump's % of the vote if DC is included as can be seen in the graph below.
There are states with high rates of hate groups but low rates of reported hate crimes such as Arkansas and Mississippi (with zero reported hate crimes). Are the groups more cautious in these states or are hate crimes less likely to be reported there? I don't know the answer to these questions but they merit further study.