Many people fear that after the fiscal cliff of 2013 the US is in the same situation as in 1937. After the tremendous Roosevelt government stimulus from 1933-1936 came the bill and that austerity caused below trend growth from 1937-1942 including a big recession. Also it originated inflation after the deflation period. World War II made an end to the bad period, but only after 1949 growth really came back.
It is at least as likely that you can compare the current situation 2000-2012 with 1937-1949.
In 2000 it was not government spending that had to go back, but business spending that had been way too high from 1996-2000. After 2000 you got artificial economic growth, not from a world war, but from the housing market used as ATM. The bill came in 2007 and the damage was big but unlike 1937 there were some positive developments in the world: the emerging markets, especially China, helping the world economy and the ICT Revolution helping productivity growth. Also monetary policy was better than after 1929.
In 2010 new problems arose in Europe. This was a bit comparable with 1946 when many of those no longer necessary soldiers didn’t do productive work as was hoped for. Europe was weak and its currencies were not trustworthy, only the US Dollar was a safe investment (like 2012). Interest rates in the US set a record low in 1946 and remained very low until c. 1953.
In 1949 people looked back and concluded a man sound of soul and mind should no longer invest in equities. Since 1929 dividends had not been rising and prices and dividends were very volatile, so safe US government bonds delivering 1-2% were the preferred investments. The Fed had promised to keep the FED rate very low for an extended period. US government debt was far above 100% of GDP. German bonds and equities were of course way too dangerous and interest rates were rightfully much higher than in the US.
So this all sound familiar. The case for 1949 is equally interesting as the case it is now 1937.
In 1953 suddenly all the pessimism was thrown away: a strong belief arose that dividends were structurally growing and that dividend yields should be below the government bond yield. This belief continued until 2008, then the opposite was thought again like in 1949. Like in 1949 people think now that it is unclear that dividends will grow and looking back… one should better not do so…
To keep it comparable with 1949 there must arrive something that causes higher economic growth than in the previous decades and uncertainty has to go down.
That something ought to be: things have to be better than thought now and for in a few year believable reasons. It is not so difficult to see what that should be: continuing growth in Emerging Markets making them an excellent market for exports and cheap imports (like after 1949 Europe was the Emerging Market from the ashes of WWII), a believable plan to get growth back in Europe (ECB/ESM financing enough, infrastructure building etc), like the Marshal Plan and a wave of innovations like after 1949 (because of WWII a lot of innovations were stalled and they exploded after 1949). That wave of innovations is already visible in the growing force of the ICT Revolution with its internet networks of tremendous force and knowledge (never in history grew Knowledge so fast as in the past decade).
All in all, I think it is more like 1949 than 1937 now.