A number of other factors like a considerable immigration flow from mainland Italy, the interior rural exodus to urban areas, where Sardinian is spoken by a much lower percentage of the population, and the use of Italian as a prerequisite for jobs and social advancement actually hinder any policy set up to promote the language. Therefore, following the model proposed by a UNESCO panel of experts in 2003, Sardinian is classified by UNESCO as a "definitely endangered" language ("children no longer learn the language as mother tongue in the home"), on the way to become "severely endangered" ("the language is used mostly by the grandparental generation and up").