Long periods of unemployment may also be seen in a negative light by prospective employers. Moreover, studies have shown that youth with long periods of initial unemployment continue to experience "wage scarring" throughout their careers, as they are never able to catch up to their peers in terms of expected salaries for their skills and experience (Nelson and Reiso, 2011; Gregg and Tominey, 2004). In most developing economies opportunities for youth are concentrated in the informal sector, where poor job security, low wages, and limited chances for on-the-job learning restrict the ability of young people to leverage such jobs to secure better, more formal work.