City AM's Editor, Allister Heath, leads today with the headline 'Never Trust UK economic statistics.' In his article, he laments the lack of reliable data with which to gauge whether - and how fast - the economy is recovering. But, he has also touched on a wider political challenge.

Despite the arrival of 'Red Ed', British politics will continue to follow the trend (since the end of the Cold War) of becoming more empirical and less ideological. The debates today - on the economy, on public services, on the environment, etc - will be won or lost by advocates who most effectively arm their principles with the ammunition of hard data. And it is getting more difficult to find data we can rely on.

Heath makes the point about economic statistics. The government's establishment of an independent Office for Budgetary Responsibility is, in part, a response to the need for trustworthy data - immune from political sleight of hand - on public spending and government debt.

Elsewhere, the problem is rife. For years, police chiefs and Home Office Ministers have cited selective crime figures to burnish their credentials. They can't be relied upon. Take violence. Under Labour it dropped, if you use the British Crime Survey measure. But, that failed to count homicide, persistent attacks and (until recently) attacks on children. On the other hand, police-recorded violent crime increased. But, because the government changed the recording procedures, it is unclear by precisely how much. For example, in Elmbridge, violence against the person doubled between 2002 and 2010 - but the local force insists this is not an accurate reflection of what really happened. Bottom line - I have no reliable data to go on.

The answer - at least for crime figures - is to make their production and commissioning totally independent of the Home Office (probably at the Office for National Statistics). If we introduce elected police commissioners and expand local crime-mapping, reliable crime figures will become even more important - so local residents can both judge the performance of their local commissioner, and the success of the government's national reform.