Within the age group 16 to 30 in Germany, men outnumber women by more than 600,000 (9%). Hundreds of thousands less desirable men will have no prospect of finding a partner at all. This demographic imbalance can result in violence and is a threat to the stability of society. A probable cause is Germany taking in mainly young male refugees since 2015, instead of more vulnerable groups such as women and children. The government should take this problem into consideration when formulating immigration policy.

The sex ratio is the ratio between numbers of males versus females. A ratio of 1 means equal numbers, a ratio above 1 means more men than women, a ratio below 1 more women than men. It is subject of much academic study, especially in China where the sex ratio at birth is wildly out of balance due to the one-child policy. In recent years the sex ratio at birth in China has been as high as 1.15 due to practices such as sex selective abortions.

I studied the sex ratio in European countries, focusing on young men and women ages 16 to 30. I assumed this is the most relevant age range for partner selection. Using demographic data from the United Nations (2016, the most recent data available) I found that Germany had the highest ratio by far, a shocking 1.09. This means that there are 9% more young men than women in Germany:

This ratio has only recently become so high. Here is the trend over time:

And here are the raw numbers. The difference between the number of young men and women was more than 600,000 in 2016:

A logical explanation is the influx of migrants since 2015, a majority of which have been young males, according to the Federal Statistics Office of Germany, the Statistisches Bundesamt. These are their official figures:

 According to scientists, as summarized in this article, when there is a shortage of women available as a partner, young men will be more (sexually) frustrated and violent, both towards other men and towards women. This negative behavior will be especially visible in low status men. This effect seems already visible in the homicide rate according to the World Bank, which has risen sharply in 2016: