The study looked at how changes in the way monetary policy is set affect the economy's response to those changes. By analyzing data from 1969 to 2005, the researchers found that after 1979, the economy responded differently to monetary policy shocks. While before 1979, output and prices decreased significantly in response to these shocks, after 1979, the response of output was not significant and the response of prices was weaker. This change was attributed to successful monetary policy leading to a more stable economy during the "great moderation" period.