What caused the “great disinflation”?

When we look at the evolution of inflation in the United States and Europe, we see strong disinflation from 1980 to 1999 and again after the 2008-2009 subprime crisis. What caused this “great disinflation”? Possible explanations are: The opening-up of trade with emerging countries with low production costs; The shift to monetary policies consisting of inflation targeting and central bank credibility; The decline in wage earners’ bargaining power under the effect of labour market deregulation and in particular the sharp decline in the degree of wage-price indexation. Empirical analysis of past developments suggests that the primary explanations for the disinflation are: The monetary policy reaction to inflation in the 1980s, but not in the 2010s; In both periods, the slowdown in wages.