I'll just go by the conclusion of Roger A. Freeman, author of "The Mighty Eighth" and a consultant for the National Museum of the Mighty Eighth Air Force. The museum’s study department is today known as the ‘Roger A. Freeman Eighth Air Force Research Center’.
"The Eighth Air Force was looked upon by USAAF commanders as their prime instrument to test their doctrine of strategic bombardment. The supreme hope was that such a campaign could render massive devastation to the war industry of a highly industrialised nation, like Germany, so that it would be unable to supply and support its armed forces; in effect, bombing into submission. In the event the combined strength of all Allied strategic forces proved unable to achieve this against Germany. What strategic bombing could achieve was evinced in the spring of 1945, but that it was decisive with the weapons and delivery systems of the Hitler war, must always remain speculative."
Heh. You're cherry-picking.
I consider Freeman to be one of aviation history's foremost authors, and "The Mighty Eighth" is a fantastic book. So I think he's an authority on the subject, although his prime area of study was 8th AF operations, rather than economic analysis of the results thereof. The language you quote from his Chapter 30, however, is followed by these observations:
"The Eighth Air Force delivered 75% of its bombs after the Allies invaded the Continent, and it was the cumulative effect of sustained bombardment on such target systems as oil and transportation with its direct and indirect strain on German war economy, that brought the B-17s and B-24s their greatest contribution to victory."
"The effect of the US heavies from the fall of 1942 until the spring of 1944, although often spectacular, was never serious enough to have profound effect. Germany's powers of recuperation were far greater than appreciated, and the small bombs carried by the B-17s and B-24s might destroy a factory building but not the precious machine tools within. Attacks against aircraft factories, even the intensive period in early 1944, saw only a temporary decline in production. On the other hand, it has been estimated that the dispersal programme instigated by the Germans in 1943 to escape the bombing possibly cost them more lost production than through actual damage to installations. In assessing the part played by the Eighth and other Allied strategic bombing forces, the considerable tying down of personnel and material in defence, both active and passive must not be overlooked. Such manpower and material might have been channelled into extra panzer divisions and so turned the scales in a land campaign."
Which, I think, is what we've been saying.
- oldman