One of the studies that helps to 2/4  BIS central bankers' speeches  explain this positive outcome was done by DeLong and Summers (1988), in which they show that a stabilizing policy can have a medium-term impact because it is not necessarily symmetrical, and hence its importance. The troughs can be smoothed without “shaving” the peak periods in the business cycles.
Economic Developments  Global Economy Global Growth Rate (IMF Projections) 6.0  y/y % chg.  World Trade Volume 6  y/y % chg.  5  5.5  4 5.0  2020: +3.5%  4.5  3 2  2018: +3.6%  1  4.0  0 3.5  -1 CY 12  3.0  13  14  15  16  17  18  19  Global Manufacturing PMI  2.5  2019: +3.2%  Average from 1980 through 2018: +3.5%  2.0  Global economy Advanced economies Emerging and commodity-exporting economies  59 s.a., DI.