One of the most significant external effects of civil war is massive population dislocations and refugee flows across national boundaries. The effects of refugee flows remain poorly understood, however. One of the most plausible links between cross-border refugee flows and the spread of conflict has to do with the impact of migration flows on the ethnic balance of host countries.

However, there is a lack of systematic data on the ethnic composition of refugee flows, making it difficult to test these claims. In conjunction with the United Nations High Commissioner for Refugees, the research team proposed the creation of two datasets, a global one on the primary ethnic groups of refugee flows between states, and a geographically disaggregated one listing refugees’ point of origin in the sending country and point of settlement in the receiving country. These datasets were used to assess the effects of refugee flows taking into account ethnical linkages.