Fourth, even when a direct correlation between security and urbanisation exists, the direction of causation is by no means obvious. Finally, every country and every city contains so much internal variation that most generalisations across nations, let alone across regions, are rendered meaningless. The lack of clear linkages between urbanisation and most dimensions of security is true at most scales of analysis, across most countries and over time. Even when correlations can be found they do not explain very much. This key point can be illustrated by a trite example.
Personal security is higher in the most urbanised countries than in the least urbanised countries.
It is safer, in terms of most social and economic variables, to live in Britain, Japan or Switzerland than to live in most parts of Africa or India. People live much longer, eat better, and are more literate in urbanised countries than in less urbanised countries. It proves absolutely nothing about the link between urbanisation and security because it fails to explain how the links between urbanisation and variables like life expectancy, nutrition and literacy actually operate. If we are interested in the link between urbanisation and different forms of security we should be asking different questions. Perhaps most critical of all is to examine why, despite our hugely impressive economic and technological progress over the last century, we have not done a better job in removing poverty.