Ricardo Caballero and Mohamad Hammour challenged the “cleansing” view of these phenomena. These phenomena affect the lifetime consumption of a representative agent by about one-tenth of a percent, according to Robert Lucas. An empirical “rule” named for Claudia Sahm has historically coincided with these phenomena. (10[1])The “Great Moderation” saw a reduction in the magnitude and (10[1])duration of these phenomena, (-5[1])which Christina Romer credited to policy interventions. A Dating Committee within the NBER retrospectively declares the (10[2])start dates of these periods. (10[1])The early 1980s saw a “double (10[1])dip” one of these phenomena (10[1])caused by Paul Volcker’s policies. For 10 points, name this part (10[1])of the business cycle (10[1])in which economic (10[1])activity declines, exemplified (-5[1])by a “Great” one in 2008. (10[1])■END■ (10[1])