Upvote:-1
Oil.
http://www.investopedia.com/university/strength/strength4.asp
Bond yields are correlated with long run expectations of energy prices. A momentary spike in real energy price - such as occurred in the early 30s or late 2000s - will correspond with a small spike in yields, while a more lasting increase as in the 70s and early 80s will be more noticeable. Conversely, in the 40s when oil was replacing coal and prices were expected to stay low, bond yields were low as well.
Upvote:11
One important fear after World War II was renewed deflation, because of the "wind down" of government spending after the war, and a fear of rising unemployment with the return of the soldiers to the U.S. economy. Such fears were a major depressant on interest rates.
The thing that the deflationists had overlooked was the 25% national savings rate during the war years, and the fact that the average American family had nearly a year's wages in the bank, or more likely in war bonds which competed with corporate bonds for available funds). The liquidation of these nest eggs, together with "pent up demand" resulting from war time deprivation, would have been inflationary--except for the excess capacity that had been developed during the war and could now be put to civilian use.