The informal business sector in Europe is worth €2.152trn, according to experts from the Johannes Kepler University in Linz, Austria. Undeclared work accounts for one third of this figure.

Although it is astronomical, this is the lowest estimate in the past three years, thus negating the hypothesis that the underground economy was boosted by the 2008 financial and economic crisis.

On the contrary, reports Czech daily Lidové noviny, the informal sector is under increasing pressure because, on the one hand " the crisis and the lack of money has had an impact on the usual clients of the underground economy such as prostitutes and drug dealers". On the other hand, "there are the efforts of the authorities to scrounge every euro to reduce public deficits," which have improved tax collecting methods.

The underground economy today represents 15.5 per cent of the Czech Republic's GDP, that is 0.5 per cent less than a year earlier.