Do we need a moratorium on forecasts?

This year the forecasts for Germany and the world economy that were made by all national and international forecasting institutions had to be revised downwards sharply. The forecast revisions have led to some public irritation and critique. Is there not a danger of a self-fulfilling prophecy? The Ifo Institute believes that forecasting is useful precisely in these times in order to take the available information and condense it into a few useful numbers that assist politicians in taking the countermeasures they consider necessary.