Forecast intervals of net migration: The case of The Netherlands

In the Netherlands, as in many other countries, annual fluctuations in net migration are larger than those in births and deaths. As a result, forecasts of net migration are an important source of errors in population forecasts, particularly in the short run. In order to make it possible for the user to judge the usefulness of a population forecast, the forecaster should give an indication of the degree of uncertainty of the forecast of net migration. An ARIMA model can be used for specifying a statistical forecast interval. As the width of forecast intervals for migration in single years differs strongly from that of an interval for average migration during the forecast period, it is important that the forecaster indicates which type of interval is presented. A comparison of forecast intervals for net migration obtained from an ARIMA model to intervals in official Dutch national population forecasts shows that the uncertainty on migration has been underestimated in past official forecasts.