In March 1948 Rau became chairman of the German Economic Commission ("Deutsche Wirtschaftskommission" or "DWK"), which during this period became the centralised administrative organisation for the Soviet Occupation Zone and the predecessor of the future East German government. The organisation existed during a time of very difficult challenges coming from different sides. A particularly momentous event during this time was the currency reform of 1948. On 20 June 1948 the western German zones introduced a new currency, leaving the eastern zone to use the old common currency. In order to avoid inflation, the DWK under Rau's leadership, was forced to follow quickly with its own reform and issued an own currency too. In doing so, the DWK also exploited the currency reform to redistribute capital by using different exchange rates for private and state-run companies. The disagreement, which of the two new currencies should be used in Berlin, triggered the Berlin Blockade by the USSR and the western airborne supply of West Berlin.