Global Report on Human Settlements 2007 - PoA-ISS

Urban crime and violence: Conditions and trends
69
countries. For instance, while in Latin America, a household
living in a city of 1 million or more people is 78 per cent
more likely to be victimized by crime than a household living
in a city of between 50,000 and 100,000 people, the corresponding
figure for the US is 28 per cent. 146 The link
between crime and city size in developing countries can be
explained by three factors. 147 First, returns on crime are
likely to be higher in larger cities due to the greater concentration
of wealthier victims, more opportunities to commit
various types of crime, and a more developed second-hand
market for the disposal of stolen items. Second, the chances
of arresting a criminal might be lower in larger cities because
large cities spend less on law enforcement per capita, or
have lower levels of community cooperation with the police,
or require more police officers per inhabitant to effect an
arrest. Finally, larger cities have a greater proportion of
crime-prone individuals/potential criminals.
The blanket association between size, density and
crime has been the basis of attempts to stop or limit the size
of new residential developments in many cities and to halt
the expansion of existing residential areas, especially slums.
As suggested by cities such as Cairo, New York, Hong Kong
and Singapore, there are many exceptions when urban areas
are compared on the basis of population size alone.
Differential crime rates suggest that city size alone does not
‘cause’ crime and violence since some of the largest cities
such as New York have comparatively low rates, thus disproving
conventional wisdom. 148 Although vastly different in
scale, a study of Madagascar communes suggested that crime
was positively associated with low population densities and
feelings of insecurity and isolation, contrary to expectations
about the link between urban size, density and crime. 149
There are many dimensions to connections between
population density and crime. Confounding factors such as
culture, socio-economic development, governance and the
strength of civil society controls are arguably as important
determinants of crime and violence rates as population
density. Within cities of all sizes, crime is concentrated
within certain, generally known, geographic areas and
population density is just one of many variables that play a
role in its occurrence. There is evidence that population
density is variably related to the occurrence of different
types of crimes. For example, some US-based research
suggests that high-density cities have fewer burglaries than
lower-density cities. According to this research, motor
vehicle thefts are also higher in denser cities. 150 Reasons for
the differential effects are ascribed to opportunity, risk,
effort and reward factors that are related to residential structural
type and the opportunity for surveillance of property
that may be planned or fortuitous. For example, because
high-density residences are typically located in apartment
complexes, they are more risky and difficult for burglars to
enter than detached suburban houses with rear doors and
windows, which burglars favour because of reduced surveillance
possibilities.
In sum, city size and density measures are important
relative to predicting crime rates, but are incomplete determinants
of criminal or violent behaviour, and may be
overshadowed by other, more local, social and environmental
Box 3.3 Rapid urban growth and crime: The example of
São Paulo, Brazil
São Paulo’s population exploded at an annual rate of 5 per cent from 1870 to 2000, with the
city and its peripheral areas now hosting over 18 million people. The population of central São
Paulo expanded by 171 per cent between 1940 and 1960, and its suburban areas grew by 364
per cent in the same period, largely due to rural in-migration. Existing civil institutions were
overwhelmed by the pace and size of population growth and were incapable of dealing with
demands for services in the hundreds of illegal subdivisions that sprang up, where standards of
due process of law are low or non-existent and levels of retributive justice and vigilantism are
high. Crime increased along with the rapid pace of urbanization, such that in 1999, the city
recorded 11,455 murders, more than 17 times that of New York City’s 667 murders. One of
São Paulo’s rapidly growing suburban municipalities, Diadema, reached a murder rate of 141 per
100,000 individuals in 2003, one of the world’s highest rates. 151
factors and by qualitative and economic forces relating to
social inclusion and cohesion.
Poor urban planning, design and
management
Only relatively recently has research pointed to the urban
environment as posing risk factors associated with crime and
violence. There is increasing evidence that poor planning,
design and management of the urban environment puts
citizens at risk of death, injury and loss of property. Placebased
crime prevention and reduction theories of defensible
space, 152 crime prevention through environmental design
(CPTED), 153 situational crime prevention 154 and environmental
criminology 155 have increasingly been supported by
empirical research suggesting that physical design and
management of the built environment play a role in facilitating
or diminishing opportunities for crime and violence.
While there is no way of accurately counting the number of
incidents related to physical design or management, it has
been estimated that 10 to 15 per cent of crimes have
environmental design and management components. 156
<strong>Global</strong>ly, this amounts to millions of incidents each
year. Thus, land-use juxtapositions, street layouts, building
and site design, transportation system planning, infrastructure
improvements – especially lighting and facility and
landscape maintenance, as well as activity and space scheduling
– have been shown to have variable impacts on crime
opportunity and on the subsequent incidence and fear of
crime. 157 The lack of integration of crime prevention strategies
within comprehensive city planning practices has been
cited as a factor in facilitating opportunities for urban
crime. 158 Physical planning can make a difference in terms of
crime prevention/reduction, to more effective policing, to
informal surveillance and to the protection of persons and
property. For example, street widening programmes can
open up previously impenetrable urban areas to police and
emergency service vehicles, and the creation of new housing
or commercial developments can change traffic generation
patterns and may provide increased economic and residential
opportunities. Site design that provides increased
prospects for people to observe their surroundings can
reduce criminal opportunity.
There is increasing
evidence that poor
planning, design and
management of the
urban environment
puts citizens at risk
of death, injury and
loss of property
It has been
estimated that
10 to 15 per cent of
crimes have
environmental
design and management
components