The article presents a study on historical price data in Norway from 1777 to 1920. The researchers collected information on prices of various goods like agriculture, fishing, and manufacturing to create monthly price indices. They used a method called repeat sales to construct these indices. The study shows that there were two significant periods of inflation in Norway during 1807-1817 and 1913-1920. Despite prices increasing dramatically during these times, they eventually stabilized back to a level consistent with purchasing power parity.