The war years were a period of hiatus for the Association since the office had moved to neutral Copenhagen. However, Denmark was invaded by the German forces in 1940 and almost all normal activity came to a halt until June 1946 when the Chief Executives were able to meet once again.
The question of European economic integration and its potential effects on department stores preoccupied members who commissioned enquiries which were presented in 1951 and 1953. At the request of the General Secretary at the time, the office of the Association was moved to Geneva in 1951, where it remained for almost five years.
From the beginning, there had been suggestions that the Association undertake some joint buying activities as well as management research. A group of Association members set up the Association Internationale de Commerce et de Gestion (later to become the ACI) in 1953 with headquarters in Brussels.
On the appointment of a new General Secretary in 1955, the office of the IADS moved back to Paris where it has been ever since. The constitution of the Association was changed in 1959 allowing more than one company per country to become a member. This led to a relatively important increase in the number of members during the 1960s. This was also the beginning of one of the strongest periods for department stores themselves, characterised by growth, development and high productivity.
Practically from its beginnings, the IADS has offered a monthly digest of relevant retail news from around the world, either in paper form or, as now, online.