The sums involved seem rather low in terms of actual GDP. That German industry was entirely destroyed along with the whole Trümmerfrauen thing have mostly been disproved, it seems.
The requirements to take on American management practices and reorganize seems to be the most important aspect.
Further, US exports only accounted for about 4% of GDP through the 50s - it seems that the boom was entirely domestic - and European countries all experienced their own similar "economic miracles" - so the common idea that the US (or e.g. Sweden) prospered due to everywhere else being destroyed seems rather flawed.
To what degree is this correct?
/u/Shashank1000
I actually wrote about the Italian economic recovery after WWII in this previous answer which, predictably, examines the role of the Marshall Plan.
In short, the Marshall Plan most certainly accelerated post-war economic recovery, but doesn't really explain the spurt in economic growth between the mid 1950s up to the late 1960s.
In September of 1947, under the strain of debts, reconstruction, a newly-constituted welfare system in great part construed to support returning veterans, as well as postwar military obligations, the British government found itself with no choice but to suspend the pound sterling’s convertibility to the U.S. Dollar, effectively going into default. With nearly all of Europe suffering from a deep balance of payments deficit with regards to the United States, the American State Department came to believe that Europe was on the brink of economic collapse, or worse — communist revolution. By the following year the United States Congress undertook to accelerate European reconstruction through the famous Marshall Plan. However, the US congress’ worries tied to American dollars being funneled into European social welfare programs led to the Marshall Plan being intentionally capped at a lower level than expected, which had the effect of creating concerns tied to the United States’ role as guarantor of Europe’s peace and prosperity.
Indeed, Marshall plan money had come at the cost of submitting portions of economic policy to the intergovernmental Organization for European Economic Cooperation (O.E.E.C.), which was itself monitored by the European Cooperation Agency (E.C.A.), an agency mostly staffed by prominent American former businessmen. This led to an appreciative, albeit guarded, attitude towards the US by European policymakers. And Europe’s problems tied to the Marshall plan didn’t stop at compromises of sovereignty either: The inflow of Marshall plan money into the western zones of occupied Germany, along with the perception by the U.S.S.R. that the government of the United States was attempting to permanently tether western Europe to itself, led the Soviet Union to further strengthen its hold on eastern Europe in addition to blockading the jointly-occupied city of Berlin. Although the blockade was rendered irrelevant by the famous Berlin Airlift orchestrated by the United States with the contribution of Great Britain, the feeling that western Europe was on the cusp of a new occupation, either economic by the United States, or military and political by the Soviet Union, became pervasive. European legislators came to the conclusion that Western Europe would have to become, as fast as possible, a “third force” capable of standing up on its own.
A political history of Europe after the Second World War that examines the mood and intent of major decision makers before, during, and after the Marshall Plan is European Integration by M. Gilbert