An interesting take on GDP stats and those who make the predictions. An analysis of economic growth forecasts for several emerging markets over 2006-2010 has led Renaissance Capital economist Mert Yildiz to conclude that analysts of Turkish origin (and he is one) tend to be: 

a) far more pessimistic about their country’s economic growth outlook than the foreigners, and 

b) more pessimistic than economists from Poland, Russia, India or China are about their respective countries.

In fact, in each of these countries, foreigners provided more optimistic GDP forecasts than the locals, Yildiz found. What is surprising about Turkey is the extent to which local analysts have tended to underestimate growth — the figure below shows an average deviation of minus 1.7. In Russia, locals’ deviation was second-largest at minus 0.5.

Yildiz comes up with several explanations, including a very attractive one about the inherently pessimistic nature of Turks as a people.