The city is often regarded as a dystopia. The city never sleeps. There is constant movement in the streets. Glaring lights shine everywhere. Tall buildings loom like taut sails in the wind. The city dizzies people, disorientates and hypnotises them. This is how Fritz Lang, the maker of the 1927 movie Metropolis, depicted the city of 2026. Now, almost a century after the film's creation, the city is actually associated with many positive things. Cities provide spaces for innovation, recreation, greening, sustainability and creativity. And yet studies on cities also present a gloomier picture. Cities are afflicted by structural issues such as poverty, social inequality, unemployment and inadequate housing. These issues are detrimental to the quality of life and safety in cities. After all, the wealthier and more spacious cities are, the less safety is an issue for them.

This dichotomy visible in and between cities is a cause for concern. First of all, there is the inequality that exists between different cities. Instead of joyful synergy or healthy competition, cities find themselves struggling with an imbalance between growth and contraction, between economic attraction and decline. Cities are being hit by the massive cuts to public spending that have taken place in the past few years, putting significant pressure on public services. In 2012, one in four Europeans lived in poverty or were at risk of poverty. Of Europe's 500 million citizens, 125 million are struggling with socio-economic shortages on a daily basis. Between 2009 and 2012, the number of Europeans living in poverty increased by 10 million. Cities are therefore dealing with a growing need for public funding for benefits, public services and health care, and doing so in the face of shrinking budgets.

Cities are faced with a wide range of problems, such as immigration, the ageing population, unemployment, social marginalisation, poverty, unaffordable housing, congestion and pollution. Although no direct causal link can be drawn between these problems and the increase of criminality and unsafe streets, they are certainly indicators that weigh negatively on safety in cities. What is also tricky is that these are stubborn problems. People who are living in poverty now will pass this problem on to future generations, providing the problem with a structural, long-term, cumulative character. Women, children, single-parent families, low-skilled workers, migrants and other vulnerable groups such as the disabled are all risk groups for poverty.