The following is a response from Martin Ravallion, director of the Development Research Group of the World Bank, on last week's Aid Watch post, We must know how many are suffering, so let’s make up numbers. Pull your head out of the sand Bill Easterly!
Faced with all these perceived “impossibilities,” Easterly and Freschi would apparently prefer to wait and see rather than take action when it is needed, based on the information available at the time. Forecasting is impossible in their eyes. What then is possible? The crisis will probably be over before we will no longer need to make forecasts or estimates to fill in for missing data. Counterfactual analysis of the impact of a crisis is also deemed to be “impossible,” even though the pre-crisis expectations for growth in developing countries are a matter of public record—hardly impossible to know! My Economix article last week defended forecasting against this type of analytic paralysis in the face of uncertainty.
Easterly and Freschi also suggest that the numbers coming from the international agencies are a muddle. Granted there are differences, but Easterly and Freschi have manufactured a good deal of the perceived muddle by mixing forecasts of different things made at different times (and hence with different information). As they could have readily verified, the 89 million figure quoted in the World Bank’s G20 paper is the estimated impact of the crisis on the number of people living below $1.25 a day by the end of 2010 based on our latest growth forecasts, as of mid 2009. “Impact” is assessed relative to the pre-crisis trajectories, as expected at the beginning of 2008.
The uncertainty about these numbers is, of course, acknowledged. But they appear to be the best estimates we can currently make given the information available.