Demographic engineering is deliberate effort to shift the ethnic balance of an area, especially when undertaken to create ethnically homogeneous populations. Demographic engineering ranges from falsification of census results, redrawing borders, differential natalism to change birth rates of certain population groups, targeting disfavored groups with voluntary or coerced emigration, and population transfer and resettlement with members of the favored group. At an extreme, demographic engineering is undertaken through genocide. The term "demographic engineering" is related to population transfers (forced migrations), ethnic cleansing, and in extreme cases genocide. It denotes a state policy (such as population transfer) to deliberately effect population compositions or distributions. John McGarry states that during a territorial dispute—and especially before negotiations—the disputants often try "to create 'demographic facts' on the ground which undercut the claims of competitors, strengthens one’s own claims, and present fait accomplis at negotiations". He cites many examples of demographic engineering, including the former Yugoslavia, Cyprus dispute, Germans in Poland, Arab-Israeli conflict and Ossetians in Georgia. Although he restricts demographic engineering to state policies, McGarry also notes the existence of "a grey area where state representatives use surrogates to inflict violence on minorities" or fail to prevent mobs, as occurred with the anti-Jewish pogrom Kristallnacht and anti-German violence in interwar Poland. The aim of demographic engineering does not have to be ethnic homogeneity. Before the rise of nation states demographic engineering was used to secure the newly conquered territories of empires, or to increase population levels in sparsely populated areas, often having strategic importance for imperial trade routes and increasing the political and economic power of a privileged ethnic group.