The modern economy began to expand, based on commercial export of seafood. The modern generation rejected many traditional foods, embracing the concepts of "freshness" and "purity" associated with ingredients from the sea, especially when marketed abroad. During the urbanisation boom of the late 1940s, many Icelanders formed regional associations in Reykjavík. As fraternites, they revived some old culinary and other rural traditions. These associations organised midwinter festivals, where they started serving "Icelandic food", traditional country foods served in a buffet. This was later called Þorramatur.