Computer browsers

DO COWS improve the view? That is a question which interests the Swiss government, given that it subsidises farmers heavily to graze their cows in the mountains. One justification for the subsidy is that cows eat young trees, and fewer trees mean better vistas of the sort beloved by tourists. But just how much do cows improve the view and where do they provide most value for money? To help answer these questions, Kai Nagel and his colleagues at the Swiss Federal Institute of Technology, in Zurich, have developed computer models of the Alps and populated them with virtual tourists (or "autonomous agents" in computer-speak) that can wander the electronic landscape.