A celebration of four excellent years for the world economy and warnings that the good times could end in tears：that sums up the views of Raghuram Rajan，the International Monetary Fund's chief economist.
Speaking to the Financial Times in London ahead of the IMF and World Bank's annual meeting in Singapore this weekend and writing in today's newspaper，Mr Rajan shows that the fund is happier about both the underpinnings of the world economy and its prospects.
A leak of the fund's economic forecasts，published in the FT last week，showed it now expects global economic growth of 5.1 per cent in 2006，compared with its previous forecast of 4.8 per cent in April.
These figures and Mr Rajan's thoughts will be confirmed in the publication of the IMF's World Economic Outlook today. In 2007 the fund expects a slowing of advanced economies but with emerging countries powering ahead，the world is still set to grow by 4.9 per cent.
A new concern Mr Rajan expressed while talking to the FT Financial Times，was that the productivity gains that have underpinned the world economy might peter out as fresh policy reforms stall.
"What I see now is the urgency for policy reform is rather muted" he says.
Mr Rajan disagrees with the growing voices predicting a recession next year. "The risks are two-sided" he says. Inflation and a US slowdown are risks to the US. "The million-dollar question is whether the slowdown is enough to quell the inflationary pressure or whether you need more rate rises."
But the elephant in the room as far Mr Rajan is concerned is still the yawning global trade imbalances that result in a huge US trade deficit and correspondingly large surpluses in China，oil exporters and Japan.
For the past 18 months，the fund has warned of a disorderly unwinding of these imbalances，involving a slump in the US dollar，much higher global interest rates and a global recession，risking chaos in financial markets and a resurgence of protectionism.
It has called on the US to reduce its budget deficit，Europe and Japan to speed domestic economic reforms，China to boost consumption and revalue the renminbi，and the rest of Asia to increase investment. and "greater exchange rate flexibility in emerging Asia"，a euphemism for Chinese revaluation of the renmimbi.
