Government ministers will often point to the toughened and tooled-up criminal justice system brought in by successive Labour home secretaries as the reason for the drop in crime. It is easy to see why this is an attractive argument, but it is far from clear that Labour’s initiatives have had a significant effect.

Between 1997 and 2007-08, crime fell by 39 per cent, according to the British Crime Survey.

Most of Labour’s reforms were not implemented until its second term, starting in 2001. Yet it was during that first term that the largest drop in crime took place. From 1997 to 2002 crime fell by 22 per cent, slowing to 18 per cent between 2003 and this year. The sharpest fall of all happened between 1995 and 1997, before Labour was even in office. The more it tinkered, the conclusion would appear to be, the less impact it had.

Looking at crime types, it is possible to offer plausible explanations for some of the changes. Significant improvements in vehicle and home security, for instance, must go some way to explaining the fall in car crime and burglaries. The changing demographics of Britain, which has fewer young men - who traditionally are the target for criminal justice interventions - might explain some of the falls, as might generalised cultural changes.

Another explanation compares crime trends with economic trends. Thus the sustained rise in crime during the 1980s and early 1990s corresponds somewhat with unstable conditions. The period of falling crime corresponded with the generally improved economy from the mid1990s on.

However, the fit is only partial. A stronger correlation might be found with changing levels of income inequality, which grew dramatically from the late 1970s to the early 1990s, when crime was rising. As income inequality stabilised from the early 1990s, albeit at a higher level, crime fell.

While ministers congratulate themselves, it is also worth remembering that the big fall in crime was preceded by a big increase - 25 years ago crime levels were much what they are today. We have, in some ways, come full circle.

Comparing Britain with other EU countries, our levels of violence and homicide remain high. There are also reasons for being sceptical of overblown claims about crime trends.

Though useful, the crime survey is far from an accurate index of all the ways individuals experience crime victimisation. Ministers might want to crow about their apparent success. But they probably should not crow too loudly.

Richard Garside is director of the Centre for Crime and Justice Studies at King’s College London.

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