Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte.Economic forecasts are an important element of rational economic policy both on the federal and on the local or regional level. Solid budgetary plans for government expenditures and revenues rely on efficient macroeconomic projections. However, official data on quarterly regional GDP in Germany are not available, and hence, regional GDP forecasts do not play an important role in public budget planning. We provide a new quarterly time series for East German GDP and develop a forecasting approach for East German GDP that takes data availability in real time and regional economic indicators into account. Overall, we find that mixed-data sampling model forecasts for East German GDP in combination with model averaging outperform regional forecast models that only rely on aggregate national information.Economic forecasts are an important element of rational economic policy. In a federal state like Germany, not only aggregate macroeconomic projections but also forecasts on the state level are crucial. Government expenditures for infrastructure, for example, should reflect expected long-run regional economic developments. In the short run, high-quality forecasts of economic activity are important for the projection of future government revenues and solid budgetary planning. Although regional differences in tax revenues of the German states are largely smoothed by the fiscal transfer system, total revenues of the states and their municipalities also depend on the regional and local economic development. Furthermore, disaggregated macroeconomic projections can also improve aggregate tax forecasts. The German income tax is progressive, that is, the marginal tax rate depends on the income level. This implies that the effect of an increase in GDP by one Euro in a high-income state on federal tax revenues is larger than of the same increase of GDP by one Euro in a low-income state. In terms of GDP per capita, there are still relatively large differences between West and East German states. In 2018, GDP per capita was between 34 thousand Euro (Schleswig-Holstein) and 66 thousand Euro (Hamburg) in West Germany and between 28 thousand Euro (Mecklenburg-West Pomerania) and 31 thousand Euro (Saxony) in East Germany (without Berlin). GDP per capita in the "poorest" West German state is still larger than GDP per capita in the "richest" East German state. Moreover, GDP per capita lies in a much smaller range across East German states than across West German states. Therefore, we...