When hidden transactions are said to equate to anywhere between a quarter and a third of a country's GDP, any government should rightly get alarmed - and Bulgaria has been no exception in this regard. In the face of a number of seemingly troubling estimates of the scope of the country's dodgy accounting practices, the Bulgarian government has taken measures to ensure businesses pay the sovereign no matter what their accounts show. Problem is, trying to get a handle on the accuracy of grey economy estimates remains a controversial business.