Those walking the streets of London late at night may soon be at risk of being mugged by gangs of investment bankers, driven to acts of desperate violence by the travails of the credit markets. That was not exactly the message of a leaked document from the Home Office; it provides, instead, a catalogue of ways in which economic strains may or may not lead to crime.

Some seem straightforward enough: people who lose their jobs may turn instead to burglary and theft to get what they want. This may have been what Tony McNulty, the Home Office minister responsible for policing, was referring to as “blindingly obvious”. Other chains of logic are stretched to extravagant lengths: economic hardship may turn more people into racists, which may aggrieve victims of racism, which may lead to more terrorist attacks.