At what age can you babysit a toddler?

A mother has been given an official police caution for leaving her 14-year-old son in charge of his three-year-old brother, it emerges. At what age can children be left at home alone without parental supervision?

Source: http://www.bbc.co.uk/go/rss/int/news/-/news/magazine-12380329

green bay packers chile earthquake uplink josh freeman nfl playoff schedule 2011