Not in Kansas Any More

I put together a series for commodity prices as measured by various CRB indexes. Since there have been a couple of new CRB indexes introduced at certain times, and the new indexes have each eventually supplanted the earlier version, I patched together a series going back to 1950 using the "current" version of the CRB index at each point in time. (I'm looking at closing prices at the end of each month.)

Over 58 57 years, from the beginning of 1950 1951 through the end of 2007 (and through the first half of 2008), the biggest drop over any 3-month period was 20%. From August to November of 2008, it has been 37%.


UPDATE: Actually, if you use the CRB Spot Index, apparently the only one available before 1974, the contrast is even more dramatic. The biggest 3-month drop 1951 though 2007 is 14%. Over the last 3 months it has been almost 27%.

Interestingly, prior to 2008, the biggest drop in the spot index comes at a different time than the biggest drop in the futures index (even though both drops are during the period when both indexes are reported). The biggest drop in the spot index was from July to October 2001 (a time most readers will remember, especially those who were working in Lower Manhattan). The biggest drop in the futures index was from November 1974 to February 1975, where it's harder to find an obvious event to explain the drop. (The fastest part of the drop was in December 1974. The US was going deeper into what was, at the time, the worst recession since the Great Depression. Perhaps someone who is old enough to have been an adult at the time can remember something more specific, but I'm at a loss.)

Also note the corrections above. The data start in 1951, not 1950.