Has corruption got worse or do we just think it has?

The most prominent of the world's anti-corruption non-governmental organisations, Transparency International, recently announced the results of its 2013 Global Corruption Barometer.

As ever, the results make interesting reading. With 114,000 people and 107 countries and territories now included in the survey, the barometer gives a fascinating insight into how corruption is both perceived and experienced across the globe. A whole range of institutions, from the police and political parties to the military and the media, come under the microscope, with many coming out with less than flying colours.

Depressing though much of the analysis can appear - citizens of 83 countries believe corruption has got worse over the past two years, for example, whereas citizens of only 11 territories think the situation has improved - it is worth remembering two things when looking at surveys such as these.

First, while Transparency International researchers make every effort to be rigorous when collating their data, we should be careful not to read too much into the detail of their findings. Corruption may well be widely perceived to be a problem that is getting worse, but that doesn't actually mean it is the case. Perception is not reality and at times the two can diverge considerably. That doesn't make the data invalid, but we should be wary of interpreting too much from simple survey questions.

Second, it should come as no surprise that certain institutions fair badly across the board. In many places, the police are widely viewed as corrupt; unsurprising given that many of the corrupt practices people actually see involve "facilitation payments".

Politicians also have lots of ground to make up, with citizens of 51 territories rating political parties as the most corrupt institution. While politicians frequently do little to help themselves in this area, there is also a problem of managing expectations.