How much did World War II boost post-war growth?
Petros Milionis and Tamas Vonyo have a new paper on this question (click through to the first pdf here), the effect was a major and long-lasting one, here is part of the abstract:
…this reconstruction process was an important driver of growth during the post-war decades, not only in Europe but globally, and its impact on growth rates lasted until the mid 1970s. Moreover, a counterfactual analysis suggests that in the absence of the reconstruction effect global growth rates from 1950 to 1975 would have been on average 40% lower and only slightly higher than those observed during the years from 1975 to 2000.
Here is Alex’s MRU video on the Solow growth model, part two here.