Why did the IMF predict in each and every year that the downturn is over and the economy is going to grow in the next year? Is this perhaps a positive psycholog

Why did the IMF predict in each and every year that the downturn is over and the economy is going to grow in the next year? Is this perhaps a positive psychology thing? Or is it only IMF? I've tried to find other predictions, and for example, the World Bank seems to be counting with a less rosy 2.9%: http://www.cbsnews.com/news/world-bank-downgrades-global-economic-forecast-for-2016/ http://www.cbsnews.com/news/world-bank-downgrades-global-eco...