The Wennberg International Collaborative (WIC) was created in 2010 to provide a network for investigators whose active research is in the study of medical practice variation within countries. This field is well established in some countries, such as the U.S., U.K. and Canada, and is growing in many others, including Switzerland, Italy, Spain, Australia, the Netherlands and more. Various publications focused on geographical variation in health care, such as quality, equity and efficiency and their relevance on health care and policy, can be found below, organized by country and publication type.