One often hears from people with far-right views that immigrants are a threat to "our women." Now, there's empirical confirmation that perceived competition for female attention is a key factor behind anti-immigrant hate crime.
Rafaela Dancygier, Naoki Egami and Amaney Jamal from Princeton University and Ramona Rischke from Humboldt University in Berlin have published a paper in which they mapped German hate crime statistics onto the country's mating market. They found the incidence of hate crime was higher in municipalities with a relative shortage of women, especially in those where there's a surplus of low-earning men, who face the toughest competition for women.