Squatting is the action of occupying an abandoned or unoccupied area of land–or a building, usually residential—that the squatter does not own, rent or otherwise have lawful permission to use. Author Robert Neuwirth suggested in 2004 that there were one billion squatters globally. He forecasts there will be two billion by 2030 and three billion by 2050. Yet, according to Kesia Reeve, "squatting is largely absent from policy and academic debate and is rarely conceptualised, as a problem, as a symptom, or as a social or housing movement."