# Why do economic cycles include downturns, but not upturns?

The United States has experienced economic downturns, or recessions, roughly every 5-10 years since they began being tracked in the late 18th century. 1785, 1789, 1796, 1802, 1807, 1812, 1815, 1822, all the way to 1937, 1945, 1949, 1953, 1958, 1960, 1969, 1973, 1980, 1981, 1990, 2000, and most recently 2007.

What I'm confused about is, assuming the economy falls on some balanced distribution around the mean, there should be equally as many economic upturns, booms, or manias if we want to borrow a term from psychology, as there are downturns, recessions, and depressions.

Yet as far as I can tell, this isn't the case. The economy goes from neutral to negative and back, with an occasional foray into positive, showing a clear bias for negative periods over positive ones.

Why is this?

• Do you think the USA economy today is larger or smaller than it was in 1785? Why do you think "the economy falls on some balanced distribution around the mean"? What is the evidence for " a clear bias for negative periods over positive ones."? – EnergyNumbers Dec 20 '19 at 7:26
• What is your definition of an upturn? – Kenny LJ Dec 21 '19 at 3:35

However, a better description would be some auto-regressive model (Here I use AR$$(1), \mu=2, \rho=0.9$$). Below you see that this could actually be some rate of some hypothetical country, again you get the same story, few recessions a lot of expansions (in the picture below 75.3% of time periods happened to be expansion periods).