A question from Yahoo! Answers:

Is the long business cycle still relevant?

Could we expect a longer period of slower economic activity during the years to come?

It’s not clear if the long business cycle (aka “the Kondratieff wave”) even exists. Modern national income accounting goes back only to 1925, data potentially convertible into modern national income accounting start in 1867. Postulating existence of the 50-year long wave based on this data is not reasonable, as we may be observing three or four unrelated secular episodes…